The Age of Mass Migration:

Economic and Institutional Determinants∗

Graziella Bertocchi

Universita di Modena e Reggio Emilia,

CEPR, CHILD and IZA

Chiara Strozzi

Universita di Modena e Reggio Emilia

September 2006

∗This is a substantially revised version of parts of CEPR Discussion Paper 4737, “Citizenship Laws

and International Migration in Historical Perspective”. Financial support from the Italian University Min-

istry and the European Commission is gratefully acknowledged. Corresponding author: Graziella Bertoc-

chi, Dipartimento di Economia Politica, Universita di Modena e Reggio Emilia, Viale Berengario, 51, I-

41100 Modena, Italy, phone 39 059 2056856, fax 39 059 2056947, e-mail bertocchi.graziella@unimore.it, web

http://www.economia.unimore.it/Bertocchi Graziella/.

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ABSTRACT

This paper studies the determinants of the mass migration waves that took place between

the Old and the New World in the period that runs from the middle of the 19th century

until World War I. We focus our attention on the institutional forces that contributed to

standard economic fundamentals. In particular, we evaluate the potential impact on migra-

tion decisions of migration policy and democracy. Migration policy is proxied by the kind

of citizenship laws (i.e., jus soli vs. jus sanguinis) in place in each country during the period

under investigation. Our results confirm the relevance of the economic factors established by

previous research. Income differentials, the level of development and the demographic struc-

ture of the population play a significant role in the determination of the rate of immigration

for the countries in our sample. However, we also find evidence of an important influence of

institutions, and in particular migration policy, since countries with a more open citizenship

policy display higher migration rates after controlling for standard economic factors. Our

results hold after accounting for the potential endogeneity of institutions, through a set of

instruments exploiting colonial history and legal origin.

JEL Classification Numbers: F22, P16, N33, O15, K40, F54.

Key Words: 19th century international migration, institutions, migration policy, democracy,

legal origins, colonial history.

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1 Introduction

A central question in the current economic debate is the importance of institutional factors in

determining economic phenomena. In this paper, we focus our attention on the determinants

of the mass migration waves that took place between the Old and the NewWorld in the period

that runs from the middle of the 19th century until World War I. This specific application

of the question of the relevance of institutions is particularly interesting for several reasons.

First of all, recent research has identified migration as a crucial channel of transmission

between institutions and economic outcomes. Acemoglu et al. (2001) link colonial migration

to the shaping of institutions themselves, and in turn to subsequent economic development.

Engerman and Sokoloff (2002) argue that the evolution of factor endowments and the extent

of inequality in New World economies crucially affected the evolution of strategic institutions

including migration policy.

Second, for the specific historical episode of 19th century mass migration, while recent

research - summarized in Hatton and Williamson (2005a) - has uncovered a number of eco-

nomic determinants, such as income and demographic differentials, the impact of institutions

has not yet been fully investigated. Institutional differentials, such as political and religious

factors, have certainly played a decisive role for other migration experiences such as the

Jewish Diaspora, or the case of the English Pilgrims. It is therefore important to establish

if similar considerations may have contributed to the determination of migration decisions

also in the case under examination.

Given these premises, in this paper we study the determinants of international migra-

tion for a sample of 14 countries in the 1870-1910 period. Beside the standard economic

determinants we also evaluate the impact of institutional factors. Out of the broad range of

social, economic, legal, and political institutions which characterize a society, for our investi-

gation we select migration policy and democracy as the potentially most relevant institutions

affecting migration decisions.

Our results confirm the relevance of economic factors established by previous research.

Income differentials, the level of development and the demographic structure of the popu-

lation prove to play a significant role in the determination of the gross rate of immigration

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for the countries in our sample. However, we also find evidence of an important influence

of institutional factors, with a country’s migration policy, as proxied by its citizenship laws,

exerting a positive impact on immigration. Thus, a more inclusive migration policy, as sig-

nalled by automatic citizenship granting to the migrants’ offspring, proves to be a relevant

factor in making relocation decisions. Our results hold after accounting for the potential

endogeneity of migration institutions, through a set of instruments exploiting legal origin

and colonial history. The degree of democracy is instead found insignificant for migration

decisions, again after accounting for its potential endogeneity.

The rest of the paper is organized as follows. In Section 2 we review the related litera-

ture. Section 3 presents the basic stylized facts of 19th century mass migration. Section 4

introduces a simple model of international migration. Our data set is described in Section 5.

Section 6 illustrates our empirical strategy. Sections 7 and 8 present our results. Section 9

concludes and indicates directions for future research. The Data Appendix collects detailed

information about the data employed.

2 Literature review

This paper represents a contribution to the literature on the economic impact of institutions.

Moreover, it adds to research on international migration in a long-term perspective. It is

therefore related to several separate branches of the literature.

The first line of research stems from the initial work of North (1981), who established

that the social, economic, legal, and political organization of a society is a primary determi-

nant of economic performance. Acemoglu et al. (2001), Acemoglu and Johnson (2005), and

Engerman and Sokoloff (2002, 2003) are among more recent contributions particular relevant

to our approach. This literature has analyzed the impact of institutions on the general level

of development. For instance, Acemoglu et al. (2001) have estimated the effect of institu-

tions on economic performance by exploiting differences in the mortality rates of European

colonizers. Acemoglu and Johnson (2005) progress along this research line by comparing the

relative strength of different set of institutions, property rights vs. contracting institutions,

for economic outcomes. Engerman and Sokoloff (2002, 2003) perform a broad comparative

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analysis of the evolution of institutions in connection with growth in the Americas. Our

innovation with respect to this line of research is to select migration as the specific eco-

nomic outcome for which we test the potential impact of an appropriately selected set of

institutions, migration policy and democracy.

Our paper also fits within the literature initiated by La Porta et al. (1998), which can be

viewed as part of the broader research body on institutions, but focuses more specifically on

legal origins. The basic premise of this research line is the recognition that laws in different

countries are adopted or transplanted through colonial heritage, and that legal origins matter

for a variety of economic issues, such as legal protection of investor rights, the quality of

government, and labor regulation. This paper relates to this literature since it evaluates the

impact on migration of the legal institution of citizenship, as a proxy for migration policy,

and exploits colonial history and legal origins to isolate its exogenous influence.

The historical experience of 19th century mass migration has been the focus of a number

of empirical studies, which have addressed both its causes and its consequences. O’Rourke

(1991), Faini and Venturini (1994), Hatton (1995), Taylor and Williamson (1997), Hatton

and Williamson (1998, 2005b), and Chiswick and Hatton (2003) examine different aspects of

world migration over the past four centuries. More specifically, Goldin (1994), Timmer and

Williamson (1998) and Hatton and Williamson (2006a,b) focus on the immigration policies

enacted in the 19th century. Recent developments in the debate on immigration are surveyed

by Borjas (1994). With respect to this research line, which typically analyzes bilateral flows

from one source country to one destination, or aggregate migration from a particular source

country or to a particular destination, we broaden our perspective to international migration

flows. Moreover, we stress their institutional determinants, beside its economic ones.

Finally, we also contribute to the literature that has modeled the political economy of

migration policy, with contributions by Benhabib (1996), Razin et al. (2002), and Gradstein

and Schiff (2006). Our empirical evidence in fact corroborates the relevance of an inclusive

migration policy for the decision to migrate.

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3 The stylized facts of 19th century mass migration

The period that runs from 1860 until World War I is usually referred to as the age of mass

migration. Economists and economic historians have already illustrated the main character-

istics of this epochal event in the previously cited literature. Table 1 presents gross migration

rates in the 1870-1910 period for the 14 countries on which our econometric analysis is based.

The source is Taylor and Williamson (1997). Our table divides countries into two groups:

Old World and New World. The Old World consists of Western European countries, which

for the period all display negative rates. Most of the European emigrants were young, poor,

and unskilled. While Ireland and Britain were the main sources of emigration initially, Ger-

many, Scandinavia and then Southern and Eastern Europe joined in during the subsequent

decades. The New World is represented in the table by Australia, Canada and the United

States, which were on the receiving side. Out of a much scarcer local population, these

countries thus exhibit highly positive rates of immigration. The main destination was North

America, followed by South America (which is not included in our sample) and Australasia.

To assess the relative importance of the phenomenon on a wider time span, Table 2

presents a long-term perspective of migration patterns for the 1870-1998 period for a sample

of countries similar to ours. The source is Maddison (2001). The table confirms the magni-

tude of the early, mass migration waves, with high net flows of migrants for the 1870-1913

period. Migratory movements slow down drastically in the interwar period, to resume in the

1950s, even if it is only after 1974 that they reach a size comparable to the early one, and

that yet only in absolute terms. While Table 2 refers to net migration, rather than gross,

this distinction is unimportant for most of the 19th century due to the high cost of returning,

even if return migration did become more significant over time.

Going further back, Chiswick and Hatton (2003) and Hatton and Williamson (2005a),

among others, have described and quantified the deep differences among the 1860-1913 mass

migration and the previous historical waves, i.e., the contracted and coercive migration in

the 1600-1790 period, and the pioneer migration in the 1790-1850 period. It is only in the

middle of the 19th century that migration flows reached the massive size that was then

sustained for over fifty years, until the outbreak of World War I. Among the factors that

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made this surge possible, there are on the one hand the improvement of the technology of

transport and communication, and on the other the European famine and revolution.

The available literature has already established which were the economic forces that

contributed to 19th century migrations. Income differentials, usually captured by a measure

of the wage gap, certainly had a paramount impact, with richer countries attracting the larger

inflows. The demographic structure of the population also mattered, because of the higher

propensity to migrate of young adults. The degree of industrialization and of reallocation of

the labor force away from agriculture initially increased and then decreased with emigration,

since in the initial stage of the development countries low agricultural wages acted as a

poverty constraint, while emigration ceased to appeal industrial workers in a subsequent,

more advanced stage. Network effects established through the stock of previous migrants

also facilitated emigration.

Despite the fact that the period under investigation is usually depicted as an era of

unrestricted migration, countries did adopt different attitudes towards emigration and im-

migration. Engerman and Sokoloff (2002) provide a historical comparison of the policies

enacted in various American countries, which included provisions regarding access to land,

public education, and suffrage extension, all meant to attract those contemplating relocation.

These policies were differentiated. When local elites were to benefit from labor inflows, they

were willing to compete to attract it. Goldin (1994) analyses the evolution of immigration

policy in the United States around the turn of the 19th century, with a focus on the debate

that eventually led to the 1917 Literacy Act, which marked a restriction of the country’s

attitude. Timmer and Williamson (1998) construct an index of immigration policy for five

destination countries (Argentina, Australia, Brazil, US, and Canada) in the 1860-1930 pe-

riod, and study their determinants. They find that policy tends to be highly persistent, and

that it responds, albeit slowly, to labor market conditions. In particular, it becomes more

restrictive as the ratio of unskilled wages over average income declines, i.e., as inequality in-

creases, while is not affected by non strictly economic factors such as xenophobia or racism.

However, their policy index is designed to reflect attitudes toward immigration rather than

effectiveness of regulation itself. Indeed Hatton and Williamson (2006b) confirm that, even

though attitudes changed a lot for the worse, as a reaction to the fact that migrants tended

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to be less skilled, policy did not change much until World War I.

In the period under consideration, political institution also exhibit considerable variation

both across countries and over time. Receiving countries tended to be far more advanced

than Europe, even though North and South America took from the beginning very different

routes of development, as reported by Engerman and Sokoloff (2002). In the Old World,

during the decades under consideration, we observe a positive evolution. Between the end

of the 19th century and the beginning of the 20th the voting franchise was progressively

expanded in Europe, under the pressure of social unrest and the need of modernization.

Acemoglu and Robinson (2000) and Lizzeri and Persico (2004), among others, report the

stylized facts of this evolution and offer for it a rationale.

4 Theory

In this section we present a simple model to guide our understanding of the potential deter-

minants of international migration. We extend to the explicit consideration of institutional

factors the presentation of basic migration theory in Hatton and Williamson (2005b), who

describe the determinants of the migration decision as follows:

dl = wf,l − wh,l − zl − c

where the decision dl of individual l (l = 1, . . . , L) in source country h to migrate to destina-

tion country f can be expressed as a function of the following variables: wf,l and wh,l are the

wages of individual l in destination and source countries, respectively, zl is the individual’s

compensating differential in favor of h, and c is the direct cost of migration. This simple

formulation can be derived from microfoundations, as the argument of an indirect utility

function. It follows that an individual is more likely to emigrate the higher is the destination

wage, and the lower are the home wage, the compensating differential, and the migration

cost. Therefore, the immigration rate will be higher for countries with higher wages relative

to the rest of the world. If the first three terms are interpreted as present values, then the de-

cision to emigrate will be more likely to be taken by young individuals, so that countries with

a higher share of young population will be associated with lower immigration. Moreover,

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ceteris paribus, a country with a larger agricultural sector should be associated with higher

emigration. However, in an earlier stage a large agricultural share may prevent emigration

by acting as a poverty constraint. Another important determinant that the literature has

discussed is the presence of a stock of previous migrants from the source country living in the

destination country. This network effect can be captured by the individual’s compensating

differential zl, or even by the direct cost c. A country with a larger stock of migrants should

therefore attract additional immigrants.

The available literature has highlighted other potential determinants of migration which

can be embedded in the above framework. For instance, skill differentials can reinforce the

impact of the wage gap. Moreover, a country’s level of human capital, as measured by the

educational level of its labor force, could affect its attracting power. However, the impact

of a country’s education level on immigration is ambiguous, at least theoretically. A high

level of education could signal liberal policies in general, thus attracting immigrants. But

it could also be correlated with higher skills for the local population, thus diminishing the

earning advantage associated with relocation. During this specific period, countries with

a low education level tended to experience large emigration, which again points toward a

positive impact of education on immigration.

In this paper, we are especially interested in the potential role of institutional factors for

migration decisions. Based on the previously presented historical evidence, we focus on two

specific factors: migration policy and the level of democracy. Within our simple framework,

the impact of a more open migration policy, which facilitates relocation and integration, can

be embedded through a decrease of the individual’s compensating differential zl, or of the

direct cost c.

Finally, the quality of a country’s political institutions can also be an important element

of attraction, because of the pecuniary and non-pecuniary costs and benefits associated with

democracy. A more democratic environment may improve the quality of the migrants’ life

per se, because it may be associated to a higher degree of equality, and because it may imply

other liberal policies regarding, for instance, land distribution and public education. Once

again, these can be viewed as factors affecting both the individual’s compensating differential

zl, or of the direct cost c.

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5 Data

For our empirical investigation of the determinants of world migration, we compile a data

set which is based on the sample of 14 countries selected by Taylor and Williamson (1997)

for their econometric analysis of international convergence in the 1870-1910 period. The

countries are: Belgium, Denmark, France, Germany, Great Britain, Italy, the Netherlands,

Norway, Portugal, Spain, Sweden, Australia, Canada, and the United States. For these

countries we assemble a panel with four observations for each country, one for each decade

under consideration. In particular, we employ the data collected by Taylor and Williamson

(1997) for decade averages of gross migration rates. Moreover, we collect from various

sources (details are provided in the Data Appendix) data on the wage gap with respect to

the other countries in the sample, the agricultural labor share, and the young adult share

of the population. The latter variable is meant to proxy for the demographic structure of

the population, while we proxy for network effect using the lagged value of the dependent

variable. The resulting data set allows to replicate, with an appropriate adaptation, the

analysis conducted by Hatton andWilliamson (1998, 2005b) on emigration from 12 European

countries in the 1860-1913 period. Their data include the wage gap, the source country

birthrate lagged 20 years as a proxy for adult cohort size, the share of labor in agriculture,

and the stock of previous emigrants to capture network effects. In addition to this basis

regressors, we also collect information on the quality of each country’s human capital — as

proxied by primary and secondary school enrollments per capita.

We complete our data set with variables meant to capture a country’s relevant institu-

tions, i.e., migration policy and democracy.

It is easier to introduce first our measure of democracy, since it is a standard one. We

use the Polity variable from the Polity IV data set. This variable includes information on

the institutionalized procedures regarding the transfer of executive power, the extent to

which executives are chosen through competitive elections, the opportunity for non-elites

to attain executive office, the de facto independence of chief executive, the development of

institutional structures for political expression, and the extent to which non-elites are able

to access institutional structures for political expression.

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Turning to the more difficult question of migration policy, a still unresolved issue is how to

measure it, and how to treat those countries that do not develop an explicit one. Moreover,

given our long-term perspective, we need a measure of migration policy that captures the

underlying trend of its evolution, rather than its short-term adaptation as a reaction to

business fluctuations and/or the outcome of political elections. Therefore, as a proxy of

migration policy, we take the citizenship laws in place in the countries under consideration.

A digression is now in order, to explain the meaning of this variable, which we are the

first to codify and employ. Each country of the world has developed a system of legal rules

that govern the attribution of citizenship, and therefore regulate the inclusion of newcomers.

Citizenship is associated with a precise set of rights and duties. It provides benefits such as

the right to vote, better employment opportunities, the ability to travel without restrictions,

and legal protection in case of criminal charges. There are also costs to citizenship, such

as the military draft, renunciation of the original citizenship, and the pecuniary and non

pecuniary costs that may be required for naturalization. Therefore, citizenship policy can

be viewed as part of broader migration policy package, even though, contrary to other

migration policy measures such as quotas and visa requirements, citizenship laws reforms

tend to be the outcome of long-term processes of adaptation often involving constitutional

amendments.

In particular, we focus on the laws governing citizenship acquisition at birth, which are

therefore especially relevant for second-generation immigrants, even though they are part

of the migration decision of any parent who cares for his children and their future. These

laws originally come from the two broad traditions of common and civil law. The former

applies the jus soli principle, according to which citizenship is attributed by birthplace. This

implies that the child of an immigrant is a citizen, as long as he is born in the country of

immigration. The latter applies the jus sanguinis principle, which attributes citizenship by

descent, so that a child inherits citizenship from his parents, independently of where he is

born. Since citizenship acquisition means full membership in a state, a jus soli legislation

should therefore be perceived as an inclusive migration policy measure.1

1To be noticed is that a jus soli legislation and democracy are not necessarily associated, since in principle

a democratic country could adopt a jus sanguinis policy, while at the same time there are historical examples

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In 18th century Europe jus soli was the dominant criterion, following feudal traditions

which linked human beings to the lord who held the land where they were born. The French

Revolution broke with this heritage and with the 1804 civil code reintroduced the ancient

Roman custom of jus sanguinis, only to reintroduce elements of jus soli in 1889 for military

reasons related to the draft. During the 19th century the jus sanguinis principle was adopted

throughout Europe and then transplanted to its colonies. On the other hand, the British

preserved their jus soli tradition and spread it through their own colonies, starting with the

United States where it was later encoded in the Constitution. By the beginning of the 20th

century, the process of nation-state formation and the associated codification effort were

completed in Continental Europe. At the same time, the revolutionary phase was over in

those countries that had been the subject of the earlier colonization era, and 19th century

colonization had extended the process of transplantation of legal tradition to the rest of the

world. Therefore, by the end of the period of interest, most countries had completed a slow

process of adjustment of their legislation regarding citizenship acquisition, in response to a

variety of largely exogenous impulses.2

We code countries on the basis of the kind of citizenship laws (i.e., jus soli vs. jus

sanguinis) in place at the beginning of each decade. The data set that we compile for the

1870-1910 period, can be described as follows. Within Europe, the jus sanguinis model

tends to dominate, but with several exceptions. Britain, as previously mentioned, always

remains a jus soli country. And so does Portugal. Scandinavian countries, as well as the

Netherlands, are late-comers that embrace the jus sanguinis legislation only towards the

end of the 19th century. France, on the other hand, leads the introduction of jus sanguinis

but switches to jus soli in 1889. Outside Europe, jus soli dominates not only in the former

British colonies,3 but also in Latin America. Despite their civil law tradition, these latter

of jus soli autocracies. Thus, our measure of migration policy differs from democracy.2After World War II, with the decolonization phase and the collapse of the socialist system, citizenship

laws have started a process of further adaptation, with a marked acceleration under the pressure of interna-

tional migration. The evolution of citizenship laws in the 1950-2000 period is investigated by Bertocchi and

Strozzi (2006).3British emigrants were actually in a special position when moving to countries belonging to the British

Empire, such as Canada and Australia, since they were dual citizens of both Britain and Empire countries.

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countries at independence chose jus soli as a way to break with the colonial political order

and to prevent the metropoles from making legitimate claims on citizens born in the new

countries.4

Finally, for each country we also collect information on additional variables which have

been employed in research on the impact of institutions: in particular, legal origin (i.e.,

common law vs. civil law), and colonial history (as captured by a dummy which identifies

the UK as the colonizer).

Table 3 reports summary statistics for the main variables in our sample. For each variable,

the maximum number of observations is 56, since we have 14 countries and four decades,

but data on some variables are missing. On average, the gross migration rate is negative

(mainly due to the important omission of Latin America), and of course displays a large

variability. We do not report net migration rates, but they are highly correlated with gross

rates (0.85). Over the (-10, 10) range of the democracy variable, countries are distributed

over the (-7, 10) interval, thus showing high variability. The wage gap and the agricultural

share are also distributed over a wide range, while the share of young in the population

and the level of education are relatively uniform. The (unreported) pairwise correlations

point to a highly significant and positive correlation between migration and the wage gap

(0.77). Migration is also significantly associated with education (0.60), the jus soli dummy

(0.33), and democracy (0.53). It is important to stress the discrepancies among the jus soli,

British colony, and common law dummies, whose means are 0.59, 0.21, and 0.29, respectively.

This confirms that these variables - even though potentially interrelated because British

colonization is associated with the spread of both the common law legal system and the jus

Hatton (1995) estimates that about 54% of British emigrants in the 1870-1913 period actually went to the

United States, while only about 42% went to Canada, Australia and New Zealand. Therefore this objection,

even if taken literally, would affect only a minority of the migrants included in our sample. Moreover, since

we interpret a jus soli legislation as a signal of a broader openness in the attitude towards immigrants, our

intuition also applies to this case.4The migration policy index constructed by Timmer and Williamson (1998) for five countries do not

include citizenship laws. Those three countries which are also in our data set (Australia, Canada and United

States) all adopt a jus soli legislation in the entire relevant period, without any modification. Therefore, our

proxy for migration policy does not overlap with theirs, which contains a different set of information and

therefore retains its independent relevance.

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soli citizenship laws - do capture different phenomena. Inspection of the pairwise correlations

is also instructive, since our two institutional variables, the jus soli dummy and democracy,

turn out to be uncorrelated (their coefficient is 0.07 and insignificant). Therefore, even if

citizenship policy could be conceptually related to democracy, because of its relationship

with suffrage, in practice the two variables do not overlap.

6 Empirical strategy

6.1 Empirical specification

We apply the intuition coming from theory and we investigate the determinants of interna-

tional migration using the following empirical specification:

Mit = a0 +E0ita1 + I 0ita2 + εit,

where Mit is the gross migration rate in country i in period t (with i = 1, ..., 1 and t =

1, ...4 - each country observation corresponding to each of the four decades included in the

period 1870-1910). Eit is a vector which includes all the economic variables which have been

traditionally used to explain the evolution of migration flows in the age of mass migration,

plus a few additional ones. Therefore, we include the wage gap, the agricultural share,

the share of young population, the interaction between the latter two, lagged migration,

and education. Iit is a vector including the institutional variables, i.e., migration policy and

democracy, which we will include one by one, and also in combination. The former is defined

by a dummy capturing the presence of jus soli at the beginning of each decade. The latter

is measured with the Polity variable from the Polity IV data set.

We can now suggest a number of specific hypotheses regarding the potential role of the

above mentioned factors, starting with the economic variables. We expect a positive effect

on a country’s rate of immigration for the wage gap. The impact of the agricultural share

is potentially ambiguous, but a negative coefficient would signal that more industrialized

countries are more attractive destinations. Similarly, countries with a lower share of young

should again be associated with higher immigration, so that the coefficient of this variable

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should be negative. The interaction term should capture the potential presence of non-

linearities. If lagged migration captures important network effects, its coefficient should

be positive, while we have conjectured that education could be associated with a positive

coefficient.

Turning to institutions, since countries with a jus soli citizenship policy should be per-

ceived by migrants as more inclusive, the coefficient of our jus soli dummy should be positive

if this factor is actually taken into account. It is important to stress that the fact that all

receiving countries in the sample apply a jus soli legislation is not invalidating our approach,

since in principle migration decisions are taken on the basis of all factors involved.5 Similarly,

if democracy matters at all, its coefficient should display a positive sign.

When dealing with institutions and their impact on the economic environment, three

different issues are to be taken under consideration. The first is their potential endogeneity,

due to the fact that these variables may themselves change over time under the influence

of the economic environment. The second issue is how to identify their specific role, given

that different kinds of institutions may be related to the same economic outcomes. The

third issue is the potential for omitted variable bias, since other factors may determine at

the same time both the nature of the institutions and the economic environment.

To investigate the causal effect of our institutional variables on international migration,

we utilize three strategies. Each of these strategies is especially intended to handle the issues

outlined above. To deal with their potential endogeneity, we use instrumental-variables (IV)

regressions, experimenting with different kinds of instruments. To unbundle their role, we

adopt a multiple instrumentation strategy. Finally, we control for country-specific factors

affecting both political and economic development by including country random effects in

our regressions.

5In other words, when considering migration, an individual will compare the implications of citizenship

laws in the destination country as part of a package including, say, wage differentials. In principle, a country

with a high wage gap could turn out to be an attractive destination despite its jus sanguinis legislation.

Indeed, there was internal migration within Continental Europe, despite the facts that most countries applied

jus sanguinis. Likewise, a jus soli country could be associated with an unappealing earning differential and

therefore be discarded as a possible destination. The latter is the case, for example, of Portugal.

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6.2 Instrumentation strategy

An IV strategy with valid instruments is the best approach to deal with potential endogeneity.

In particular, for each endogenous regressor, it is necessary to employ instruments that are

correlated with the regressor itself, orthogonal to any other omitted characteristics, and not

correlated with the outcomes of interest through any channel other than their effect via the

endogenous regressors.

In our framework, the two variables which are potentially endogenous are migration policy

and democracy. The potential endogeneity of migration policy (as proxied by our jus soli

dummy) with respect to migration is explained by the fact that, in principle, a country could

add jus soli elements under the pressure of the existing immigrants. Moreover, a country

could instead orient its legislation toward jus sanguinis in the presence of a large stock of

emigrants. To address this issue, we run IV regressions using two alternative instruments

for jus soli. The first instrument reflects a country’s colonial history and is constructed as

a dummy which takes a value equal to 1 if the country has been, or still is in the period

under consideration, a British colony. The second instrument is legal tradition and consists

of a dummy for the presence of a common law legal origin. Both variables come from

a tradition of investigation which has stressed the relevance of colonial heritage, and the

interrelated exogenous differences in legal systems, for a country’s general development level.

The argument in support of both instruments is that colonial history and legal origin could

affect the shaping of current migration policy but should have no direct effect on migration.

The potential endogeneity of democracy with respect to the general level of development

has been the subject of a long research line.6 Within the present context, democracy may

turn out to be endogenous with respect to migration, since a large pool of relatively poor

migrants may push toward political change. To address this issue, we run IV regressions

using the degree of democracy in the first decade of the sample period as instrument. Again,

the argument is that the initial democracy level could affect the current degree of democracy

but should have no direct effect on current migration.

Finally, when we analyze the joint impact of migration policy and democracy on migra-

6See, for example, Barro (1999) on the determinants of democracy, and Acemoglu et al. (2005) on the

impact of democracy on income.

15

tion, we address the presence of multiple potential sources of endogeneity by using a multiple

instrumentation strategy, in order to ascertain that the two kinds of institutions do capture

different phenomena and do not affect the dependent variable through the same channels.

Thus, we make sure that we choose for each potentially endogenous variable an instrument

which is appropriate only for it, in order to disentangle the impact of each institution on

international migration.7

7 Results

Table 4 reports our regression results on the determinants of migration in the 1870-1910

period, where only economic factors are taken into account. We present both pooled and

random effects specifications, where the latter are meant to take into account the presence

of omitted country-specific factors. In the pooled OLS version (regression 1), the coefficient

of the wage gap is positive and highly significant, confirming its crucial role as uncovered

in previous studies. The agricultural share, which captures the level of development, turns

out to display a significant negative impact, confirming that more industrialized countries

are more attractive destinations. The share of the young population, which proxies for the

emigration intensive cohort, also has a significantly negative coefficient, as expected. The

positive and significant impact of the interaction between the latter two regressors could be

due to the presence of non-linearities, possibly due to higher fertility rates in rural contexts.8

It is important to stress that the same results do carry through substantially confirmed

in the random effects specification (regression 3), thus showing that the main economic

determinants are relevant also in the presence of omitted country-specific characteristics

which are time invariant.

For the same basic specification, we also run 2SLS regressions (regressions 2 and 4) to

take into account the potential endogeneity of wage gap, due to its gradual reduction due to

7Acemoglu and Johnson (2005) similarly unbundle the impact of contracting and property rights insti-

tutions. Persson and Tabellini (2006) decompose the impact of different forms of democracy, i.e., electoral

rules and forms of government.8We also checked directly for non-linear effects of the agricultural share by adding its square to the

regression, but the coefficient turned out to be insignificant.

16

convergence, which is in turn accelerated by migration. We instrument the wage gap with

its lagged value and Panel B of Table 4 presents the corresponding first stage regressions

(without and with random effects). As the results show, the previous conclusions hold, by

and large, even accounting for this potential endogeneity. To be noticed, however, is that

the instrumentation considerably reduces the sample size, making a comparison difficult.

Table 5 explores the role of additional economic determinants. Regressions 1 and 3 (with-

out and with random effects, respectively) add the lagged value of the dependent variable,

migration, to the other regressors, to gauge the potential role of network effects. As ex-

pected, lagged migration has a positive effect, but it is insignificant. The overall pattern

for the other regressors is unchanged, except that the agricultural share loses significance.

To be noticed is that, once again, this specification considerably reduces the sample size.

Regressions 4 and 5 (again, without and with random effects) add education to the standard

regressors. The new variable has a positive, but insignificant coefficient. Its main impact is

to interfere with the share of young, reducing the significance of its coefficient in the random

effects specification, possibly because in countries with a highly educated labor force the

young have less of an incentive to migrate.

In Tables 6 and 7 we introduce our institutional variables, one by one. In Table 6 we

add migration policy, as proxied by our jus soli dummy, to the standard economic regressors

which appear in the basic specification of Table 4. Our results show that jus soli displays a

significantly positive coefficient, both in the pooled and in the random effects specifications

(regressions 1 and 4). The role of the standard regressors is confirmed and in some cases

even reinforced. Next, we control for the potential endogeneity of jus soli by running 2SLS

regressions using our two alternative instruments, the British colony dummy and the com-

mon law dummy. Panel B of Table 6 shows the corresponding first stages. The positive and

significant impact of migration policy is confirmed when jus soli is instrumented both with

the British colony dummy and the common law dummy (regressions 2 and 5, without and

with random effects, respectively), the only exception being the pooled specification when

using common law as instrument. The relevance of both instruments is witnessed by the

significance of the British colony and common law coefficients in the first stage regressions

and by the significance of the reported F statistics and Wald χ2 statistics for the joint signif-

17

icance of the instruments. The instruments relevance is also confirmed by the (unreported)

F test of excluded instruments and by the Anderson canonical correlation LR statistic. The

exogeneity of jus soli is then tested and confirmed using a Hausman test.

Overall, we can therefore conclude that a relatively open migration policy, as captured

by a jus soli legislation, proves to be a significant factor of attraction for migrants, and that

the potential feedback between the presence of migrants and migration policy itself is not

affecting this conclusion.

In Table 7, we repeat the same exercise for democracy, as measured by the Polity variable,

which is added to the basic specification of Table 4. While the coefficient of the new variable

is positive, it is never significant, both in the pooled and the random effects specifications

(regressions 1 and 3). As for jus soli, we also take into account the potential endogeneity

of democracy and we then perform 2SLS regressions (regressions 2 and 4) using as instru-

ment the value of the variable in the first decade of the sample period. Panel B of Table

7 shows the corresponding first stages. Once again, democracy is insignificant. As before,

the instrument relevance is confirmed by the significance of the instrument coefficient in

first stage regressions, by the reported F statistics and Wald χ2 statistics, and by the (un-

reported) F test of excluded instruments and Anderson canonical correlation LR statistic.

The exogeneity of democracy is then tested and confirmed using a Hausman test.

Overall, we can therefore conclude that there is no convincing evidence that democracy

affects migration choices in our sample, and that its lack of relevance is not due to its

potential endogeneity.

Finally, Table 8 jointly adds migration policy and democracy to the basic economic

regressors in order to identify their separate role as determinants of international migration.

In the OLS specification, without and with random effects (regressions 1 and 5), previous

results are confirmed, as jus soli has a positively significant coefficient, while democracy is

insignificant. Even though previous 2SLS regressions do not indicate the presence of serious

endogeneity problems for either variable, we do proceed to instrument them, first one by

one (regressions 2, 3, 6 and 7), and then together (regressions 4 and 8). For the jus soli

variable, we only present the instrumentation with the British colony dummy, which proves

more successful in Table 6. For brevity, the first stages are presented in Table 8.bis only for

18

the version with random effects. The first stage regressions confirm that our selection of

instruments allows to unbundle the impact of our different institutions: regressions 3 and

4 show that initial democracy has no influence on jus soli, while the British colony dummy

has no influence on democracy. Our second-stage results confirm the positive and significant

impact of migration policy and the irrelevance of democracy.

Overall, we can conclude that international migration in the 1870-1910 period was driven

by economic fundamentals, as established in previous studies, but was also influenced by

institutions. More specifically, even in this age of free migration, it is migration policy that

proves relevant for migration decisions, while political institutions play no role. Generally

speaking, even if the advantages of an open citizenship policy can indeed be interpreted

and perceived in economic terms, this additional regressor adds to our understanding of the

observed outcomes.

8 Robustness

To test the robustness of our results, we also study some variants of our empirical specifi-

cations, using different regressors, different estimation techniques, different instrumentation

strategies, and different measures of the reference variables. We do not report these estimates

here for brevity but we do give an account of our experiments.

Our results are derived within a framework where time effects are not present but are

also robust to their inclusion. Indeed, time effects turn out to be insignificant when added

to each of the above specifications, due to the fact that in our sample data variability

occurs more across countries than over time. We experiment with alternative measures of

income differential, such as the GDP gap (in place of the wage gap) and our reference

results are confirmed. We also experiment with additional economic determinants, such as

alternative measures of education, and with several measures of openness. However, these

additional regressors turn out to be always insignificant. We also test alternative measures of

democracy. Beside the whole range of indicators available in the Polity IV data set (i.e., the

variables Revised polity, Institutionalized autocracy, Institutionalized democracy, Openness

of executive recruitment, Regulation of participation, and Competitiveness of participation),

19

we use a dichotomous measure of democracy taking the value of 1 if the Polity variable is

strictly positive, following Przeworski et al. (2000). In all these alternative specifications,

our reference results do not change. We also try out an alternative set of instruments for

democracy. In particular, we use the value of the Polity variable in the initial available year

and a variable measuring the number of other countries in the sample that are democracies,

again following Przeworski et al. (2000). With these alternative instrumentation strategies

the irrelevance of democracy with respect to migration is again confirmed. Finally, we also

estimate our panel regressions using a fixed effect framework instead of a random effects

framework. It turns out that in all the reference specifications with both economic and

institutional determinants a Hausman test of fixed versus random effects indicates that it is

preferable to use random effects.

9 Conclusion

We studied the determinants of the mass migration of the 19th century with particular

attention to institutional factors that may have interacted with standard economic funda-

mentals. We found evidence that migration policy, as proxied by the type of citizenship

laws, did contribute to the economic forces that determined this historical event. Therefore,

beside wage differentials, the level of development, and the demographic structure of the

population, a more inclusive citizenship policy, by facilitating integration and assimilation,

proved relevant for migration decisions even in this age of unrestricted migration. Political

institutions, on the other hands, were shown to be irrelevant in this respect.

While our attention was confined to the 19th century, our conclusions do carry impli-

cations for the current policy debate on international migration and help to understand

the implications of today’s restrictive migration policy in general, and citizenship policy in

particular.

Recent research on globalization during the same historical period has highlighted trade

policy as important additional elements that may interact with the institutions of migra-

tion and democracy. On the one hand, O’Rourke and Taylor (2006) have investigated the

relationship between democratization and trade liberalization. On the other, Hatton and

20

Williamson (2006a) have uncovered a paradoxical and persistent inverse correlation between

the relative openness of trade and migration policy Trade policy could therefore represent

an important third factor linking the institutions of migration and democracy. We leave its

investigation for future research

DATA APPENDIX

Migration: Decade averages of gross immigration rates elaborated by Taylor andWilliamson

(1997) for the 1870-1910 period, which are based on Ferenczi and Willcox (1929). Historical

emigration and immigration data are also collected by Mitchell (2003). His sources are

essentially Ferenczi and Willcox (1929). The nature of these statistics varies greatly from

country to country and many data are missing.

Wage gap: Decade averages of the log of the wage ratio, where the numerator is a country’s

real wage and the denominator is world unweigthed average of the other countries’ real

wages. Only information about bilateral migration flows - which is not available for this

time period - would allow to compute for each country an appropriately weighted average.

The source of the wage data is Williamson (1995).

Agricultural share: Decade averages of annual figures. The source is Banks (2001).

Share of young population: Ratio between the young (i.e., aged 15-29) population and

population, from Census data reported in Mitchell (2003). For each decade we take the

Census closer to the year ending in 0. Note the following exceptions: for the Netherlands

the age reported is 10-29 (except in 1900), for Spain it is 16-30.

Education: Decade averages of annual figures on primary and secondary enrollment per

capita. The source is Banks (2001).

Jus soli: Dummy for countries that have a jus soli citizenship law at the beginning of

each decade. The sources are Weil (2001), Joppke (1998), Brubaker (1992), and a variety of

library sources.

Democracy: Decade averages of the Polity variable from Polity IV (2002).

British colony: Dummy for countries that were at any time British colonies. The source

is the ”Correlates of War 2 Project” (2004).

21

Common law: Dummy for countries with a common law legal origin. The source is La

Porta et al. (1999).

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25

Table 1 Gross migration rates (Migrants/1,000 Population), 1870-1910

Old World -4.17 Belgium -2.12 Denmark -2.78 France -0.19 Germany -1.47 Great Britain -5.15 Italy -9.25 Netherlands -4.18 Norway -6.55 Portugal -4.35 Spain -4.54 Sweden -5.25 New World 12.21 Australia 14.43 Canada 14.35 United States 7.86

Source: Taylor and Williamson (1997).

Table 2 Net migration (1,000), 1870-1998

1870-1913 1914-49 1950-73 1974-98 Old World -13,996 -3,662 9,381 10,898

France 890 -236 3,630 1,026 Germany -2,598 -304 7,070 5,911

Italy -4,459 -1,771 -2,139 1,617 Japan n.a. 197 -72 -179

United Kingdom -6,415 -1,405 -605 737 Others* -1,414 54 1,425 1,607

New World 17,856 7,239 12,663 21,639 Australia 885 673 2033 2151

New Zealand 290 138 247 87 Canada 861 207 2,126 2,680

United States 15,820 6,221 8,257 16,721 *Includes Belgium, Netherlands, Norway, Sweden and Switzerland. Source: Maddison, 2001.

Table 3 Summary statistics

Variable Obs Mean Std dev. Min Max Migration 53 -1.51 6.98 -17.97 22.64 Wage gap 56 -0.08 0.47 -0.89 0.77 Agricultural share 51 43.91 15.25 8.95 69.73 Share of young 55 26.29 2.66 23.34 35.85 Education 49 14.01 4.29 4.42 20.50 Jus soli 56 0.59 0.50 0 1 Democracy 53 1.83 5.48 -7 10 British colony 56 0.21 0.41 0 1 Common law 56 0.29 0.46 0 1 The panel sample is composed by four cross-sections of 14 in the 1870-1910 period. For details see the Data Appendix.

Table 4

The economic determinants of mass migration

PANEL A: Dependent variable is gross migration (1) (2) (3) (4)

Pooled OLS

Pooled 2SLS

Random effects OLS

Random effects 2SLS

Wage gap 14.311 18.845 9.647 18.404 [8.82]*** [8.02]*** [3.80]*** [5.98]*** Agricultural share -0.948 -0.796 -1.055 -1.025 [2.33]** [1.85]* [1.94]* [1.55] Share of young -1.534 -1.377 -1.452 -1.715 [2.67]** [2.19]** [1.67]* [1.70]* Agric. share. X Share of young 0.041 0.038 0.041 0.045 [2.70]** [2.53]** [2.01]** [1.83]* Constant 34.819 27.883 37.935 39.078 [2.23]** [1.60] [1.61] [1.43] Observations 50 38 50 38 Countries 14 14 14 14 Adjust. R2 0.66

PANEL B: Dependent variable is wage gap (first-stage regressions)

Pooled OLS

Random effects OLS

Lagged wage gap 0.904 0.865 [20.14]*** [12.07]*** Agricultural share -0.034 -0.015 [1.31] [0.83] Share of young -0.049 -0.013 [1.32] [0.47] Agric. share X Share of young 0.001 0.001 [1.34] [0.74] Constant 1.342 0.403 [1.29] [0.54] Observations 38 38 Countries 14 14 Adjusted R2 0.92 F-statistic/Wald χ2 237.88 220.79

Robust t statistics in brackets assume clustering at country level. * significant at 10%; ** significant at 5%; *** significant at 1%

Table 5

Additional economic determinants of mass migration

(1) (2) (3) (4)

Pooled OLS

Pooled OLS

Random effects OLS

Random effects OLS

Wage gap 14.298 13.692 15.952 10.251 [2.17]* [6.48]*** [4.77]*** [2.97]*** Agricultural share -0.864 -0.941 -1.017 -0.987 [1.72] [1.77]* [1.52] [1.76]* Share of young -1.452 -1.499 -1.69 -1.361 [2.04]* [2.06]* [1.68]* [1.53] Agric. share X Share of young 0.039 0.04 0.046 0.037 [1.82]* [2.04]* [1.78]* [1.75]* Lagged migration 0.179 0.013 [0.41] [0.06] Education 0.151 0.079 [0.52] [0.20] Constant 31.509 32.187 37.03 35.666 [1.90]* [1.57] [1.39] [1.43] Observations 37 46 37 46 Countries 13 14 13 14 Adjusted R2 0.74 0.67 Robust t statistics in brackets assume clustering at country level. * significant at 10%; ** significant at 5%; *** significant at 1%

Table 6 The impact of migration policy on mass migration

PANEL A: Dependent variable is gross migration

(1) (2) (3) (4) (5) (6)

Pooled OLS

Pooled 2SLS

Pooled 2SLS

Random eff. OLS

Random eff. 2SLS

Random eff. 2SLS

Wage gap 13.539 11.318 13.655 9.988 11.349 10.879 [9.73]*** [5.63]*** [7.52]*** [4.04]*** [2.64]** [4.54]*** Agricultural share -1.14 -1.693 -1.111 -1.143 -1.463 -1.258 [2.68]** [2.60]** [2.53]** [2.14]** [1.93]* [2.15]** Share of young -1.809 -2.599 -1.768 -1.65 -2.351 -1.931 [3.17]*** [2.97]** [3.08]*** [1.92]* [1.86]* [2.04]** Agric. share X Sh. of young 0.049 0.07 0.048 0.044 0.056 0.05 [3.10]*** [2.97]** [3.06]*** [2.23]** [1.97]* [2.28]** Jus soli 2.296 8.907 1.953 2.428 11.603 5.564 [2.71]** [1.99]* [0.60] [1.77]* [2.18]** [1.80]* Constant 40.569 57.125 39.711 41.463 55.74 45.602 [2.59]** [2.35]** [2.48]** [1.79]* [1.67] [1.82]* Observations 50 50 50 50 50 50 Countries 14 14 14 14 14 14 Adjusted R2 0.68

PANEL B: Dependent variable is jus soli (first-stage regressions)

Pooled OLS

Pooled OLS

Random eff. 2SLS

Random eff. 2SLS

Wage gap -0.63 -0.358 -0.679 -0.64 [1.75] [1.13] [2.03]** [2.18]** Agricultural share 0.109 0.099 0.052 0.056 [1.66] [1.55] [0.93] [1.04] Share of young 0.175 0.145 0.109 0.1 [1.90]* [1.57] [1.24] [1.18] Agric. share X Sh. of young -0.005 -0.004 -0.002 -0.002 [1.95]* [1.68] [1.11] [1.04] British colony 1.136 1.1 [3.19]*** [2.96]*** Common law 0.898 1.115 [3.30]*** [3.51]*** Constant -3.751 -3.553 -2.205 -2.501 [1.43] [1.32] [0.92] [1.08] Observations 50 50 50 50 Countries 14 14 14 14 Adjusted R2 0.25 0.28 F-statistic/Wald χ2 13.68 6.89 10.34 14.15

Robust t statistics in brackets assume clustering at country level. * significant at 10%; ** significant at 5%; *** significant at 1%

Table 7 The impact of democracy on mass migration

PANEL A: Dependent variable is gross migration

(1) (2) (3) (4)

Pooled OLS

Pooled 2SLS

Random effects OLS

Random effects 2SLS

Wage gap 12.998 12.968 8.672 9.89 [7.32]*** [4.97]*** [3.10]*** [3.58]*** Agricultural share -0.968 -0.992 -1.168 -1.115 [2.72]** [2.87]** [2.09]** [2.03]** Share of young -1.489 -1.584 -1.597 -1.654 [2.87]** [3.41]*** [1.80]* [1.96]* Agric. share X Sh. of young 0.042 0.043 0.046 0.047 [3.15]*** [3.33]*** [2.17]** [2.26]** Democracy 0.176 0.131 0.189 0.293 [1.22] [0.71] [0.98] [1.01] Constant 32.907 34.968 40.591 37.946 [2.31]** [2.76]** [1.70]* [1.66]* Observations 50 49 50 49 Countries 14 13 14 13 Adjust. R2 0.67

PANEL B: Dependent variable is democracy (first-stage regressions)

Pooled OLS

Random effects OLS

Initial democracy 0.73 0.701 [3.81]*** [4.10]*** Wage gap 1.068 1.598 [0.59] [0.81] Agricultural share 0.245 0.627 [0.61] [1.64] Share of young 0.199 0.809 [0.32] [1.33] Agric. share X Sh. of young -0.01 -0.025 [0.73] [1.75]* Constant -1.963 -18.036 [0.11] [1.09] Observations 49 49 Countries 13 13 Adjusted R2 0.67 F-statistic/Wald χ2 54.3 45.65

Robust t statistics in brackets assume clustering at country level. * significant at 10%; ** significant at 5%; *** significant at 1%

TABLE 8 The joint impact of migration policy and democracy on mass migration

Dependent variable is gross migration

(1) (2) (3) (4) (5) (6) (7) (8)

Pooled OLS

Pooled 2SLS

Pooled 2SLS

Pooled 2SLS

Rand. eff.2SLS

Rand. eff. 2SLS

Rand. eff. 2SLS

Rand. eff. 2SLS

Jus soli instrum.

Democr. instrum

Both instrum.

Jus soli instrum.

Democr. instrum.

Both instrum.

Wage gap 11.762 9.426 11.855 10.512 8.67 8.336 9.623 8.831 [6.93]*** [3.74]*** [5.02]*** [4.80]*** [3.24]*** [2.25]** [3.60]*** [2.88]*** Agricultural share -1.192 -1.614 -1.187 -1.423 -1.305 -1.697 -1.254 -1.518 [3.77]*** [4.00]*** [3.66]*** [4.74]*** [2.38]** [2.32]** [2.34]** [2.41]** Share of young -1.788 -2.353 -1.839 -2.147 -1.865 -2.609 -1.889 -2.321 [4.09]*** [4.00]*** [4.24]*** [4.77]*** [2.15]** [2.20]** [2.29]** [2.36]** Agric. sh. X Sh. of young 0.051 0.068 0.051 0.06 0.051 0.066 0.052 0.062 [4.36]*** [4.37]*** [4.21]*** [5.22]*** [2.50]** [2.41]** [2.58]** [2.63]** Jus soli 2.603 7.523 2.293 5.06 2.745 10.196 2.626 7.315 [2.43]** [2.24]** [2.19]** [2.01]* [2.00]** [2.47]** [2.02]** [2.15]** Democracy 0.224 0.316 0.18 0.24 0.25 0.404 0.287 0.29 [1.66] [1.54] [0.94] [1.01] [1.32] [1.52] [1.05] [0.89] Constant 38.9 50.227 40.054 46.193 45.312 60.151 42.399 50.932 [3.15]*** [3.06]*** [3.31]*** [3.54]*** [1.95]* [1.94]* [1.92]* [1.96]* Observations 50 50 49 49 50 50 49 49 Countries 14 14 13 13 14 14 13 13 Adjusted R2 0.69

Robust t statistics in brackets assume clustering at country level. * significant at 10%; ** significant at 5%; *** significant at 1%

TABLE 8bis

The joint impact of migration policy and democracy on mass migration: First stage regressions

Soli

instrumented Democracy

instrumented Soli and democracy

instrumented (1) (2) (3) (4)

Random effects

OLS Random effects

OLS Random effects

OLS Random effects

OLS

Dependent varable:

Jus soli Dependent variable:

Democracy Dependent variable:

Jus soli Dependent variable:

Democracy Wage gap -0.558 1.514 -0.71 0.525 [1.69]* [0.76] [1.89]* [0.20] Agricultural share 0.072 0.723 0.059 0.629 [1.32] [1.92]* [1.05] [1.63] Share of young 0.133 0.992 0.121 0.837 [1.54] [1.65]* [1.33] [1.36] Agric. sh. X Sh. of young -0.003 -0.029 -0.003 -0.026 [1.55] [2.05]** [1.28] [1.77]* British colony 1.286 1.304 1.914 [3.45]*** [3.05]*** [0.63] Initial democracy 0.718 -0.009 0.679 [4.04]*** [0.38] [3.90]*** Democracy -0.036 [1.95]* Jus soli -1.559 [1.64] Constant -2.672 -21.833 -2.405 -18.616 [1.15] [1.34] [0.98] [1.11] Observations 50 49 49 49 Countries 14 13 13 13 Wald χ2 14.83 45.17 11 46.53

Robust t statistics in brackets assume clustering at country level. * significant at 10%; ** significant at 5%; *** significant at 1%