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Revisiting the demand of agricultural insurance: The case of Spain1
Alberto Garrido2 and David Zilberman
(Work in progress – do not cite nor circulate without authors’ permission)
Abstract We develop an expected utility model to analyse the demand for agricultural insurance covering yield losses. In the simplest case, using CARA preferences, we show that the demand for insurance depends on the product price variability and on the correlation between yield and price. If premim subsidies and farm program subsidies are sufficiently high, insurance may be attractive even if the indemnnity scheme does not compensate for the cost of the premium. In a more general case, with DARA-CRRA preferences, we show that insurance is more sensitive to incorrectly calculated premia when prices are more volatile and when price and yield are negatively correlated. In the second part, we use the actual insurance records of 55,000 farmers and 11 years to estimate two sets of insurance demands. We define measures of insurance’s expected returns, variance and third moment, based on observed insurance data, and infer the expected returns for those farmers that have never had an indemnity. We estimate several probit models and count models for the insuring vs non-insuring strategies, in which the economic returns of insurance and its two measures of dispersion enter as explanatory variables. Results show that farmers’ insurance strategies are largely explained by their actual insurance experience as captured by these three variables. Individuals with loss rations greater than 1 do not show more responsiveness that those facing more balanced premium charges. Results show that adverse selection may not be a major source of inefficiency in the Spanish insurance system. Keywords: Agricultural insurance, insurance demand models, Spain JEL code: G22, Q12, Q14
1 Associate Professor at the Universidad Politécnica de Madrid (Spain), and Professor at the University of
California, Berkeley, respectively. Work conducted during the sabbatical year of the first author at the Department of Agricultural and Resource Economics, University of California, Berkeley. He gratefully acknowledges the generous support of this Department and the funding from the Spanish Ministry of Education (Programa de Movilidad de 2004) and of the Universidad Politécnica de Madrid (Programa de Sabáticos 2004). Special thanks go to Maria Bielza for preparing the database. Entidad Estatal de Seguros Agrarios (ENESA) of Spain provided the data used for the empirical analyses.
2 Corresponding author: Departamento de Economía y Ciencias Sociales Agrarias, ETS Ingenieros Agrónomos. 28040 Madrid (Spain). Email: [email protected].
1
1. Introduction The literature on agricultural insurance seems to provide very few succesful examples. Most
conclusions are based on a very limited number of experiences and countries, which mostly
focus on publicly provided insurance. Most world countries, developed and developing, have
agricultural insurance systems or have gone through processes of development, crises, and
revitalisation.
Conventional wisdom assumes that agricultural insurance is too vulnerable to serious
problems of asymetric information (Just & Pope, 2002; Chambers, 1989). In the European
Union, the private sector provides basic coverages for a very limited number of hazards,
indicating that many of the risks and hazards to which farmers are exposed cannot be insured by
private insurance companies. Yet, a number of countries have developed large and
comprehensive insurance policies as a means to provide safety nets for farmers. In the last ten
years, the US, Spain, and Canada, among others, have expanded their insurance systems in
terms of insured risks, kinds of policies, and their budgetary allocations to subsidise premia. The
European Commission has recently launched a reflection period to analyse alternatives to
increase the EU’s involvement in developing risk management instruments, including
agricultural insurance.
Despite its importance in terms of insured acreage, total liabilities and premium
subsidies, very little is known about non-US insurance experiences, with the exception of
Canada and a number of policy review works (OECD, 2002; EC commission, 2000). The
Spanish case is especially striking because it has a rich experience in developing new and
innovative agricultural insurance, and has been expanding during the last 25 years. And yet it
has received scant attention in the literature, and completely ignored as an alternative model to
countries in the process of developing their own systems.
This paper focuses on Spain’s agricultural insurance policies. It seeks to characterise the
demand for insurance in Spain and determine the extent to which it is vulnerable to problems of
asymetric information. By looking at a wide range of crops and insurance mechanisms, it seeks
to offer a fresh look at agricultural insurance in general and fill the gaps that prevent a more
informed view of this important safety net. The paper develops a new modeling approach that
provides testable hypotheses about farmers’ insurance demand, which are tested by simulation
models, statistical and econometric methods.
The paper is structured as follows. After reviewing the literature on insurance demand in
section 2, we provide a brief description of the Spanish agricultural insurance system and
2
primary factual data in the third section. Section 4 includes the basic model for insurance
demand. In section 5 we provide numerical results that enrich the theoretical conclusions.
Section 6 describes the database used in the statistical and econometric analyses, whose results
are discussed in section 7. The paper’s most salient conclusions are summarised in section 8.
2. Literature review on insurance demand Canada, Spain and the US are among the OECD countries with more developed agricultural
insurance policies. The three of them have in the last decade increased the budget devoted to
premium subsidisation, and the pecentages of farmers and surface with some coverage. As
rough measures, these countries spend in subsidising insurance policies an equivalent of 1 to 2%
of their total agricultural output. In response to these significant budgets allocation, about 50 to
60% of the eligible farmers purchase at least one insurance policy. On average, US spends in
insurance subsidies about US$25 per insured hectare, Spain €25, and Canada C$50.
Insurance subsidisation, though important in absolute and relative terms, is not the only
means the governments of these countries support agricultural insurance. Agencies directly or
indirectly promote research and support continuous innovation, offering a broad menu of
insurance options to field crops, fruits & vegetables and livestock farmers.
While the US insurance policy has inspired hundreds of articles and books, the Canadian
and the Spanish ones have motivated remarkable fewer works. Yet, as a whole and in view of
the variety of experiences and long history, they offer a wealth of results, conclusions as well as
unexplored research questions.
Farmers purchase insurance polices because (1) expected benefits are positive, (2) they
gain from asymmetric information, and (3) they are risk-averse (Just et al. 2003). The bulk of
the literature on agricultural insurance has focused on items (1) and (2), that have been tested
under alternative assumptions about item (3).
With insurance, asymetric information implies that insuree and insurer have different
information about productive risks and insuree’s behaviour. Asymetric information is thought to
provide incentives for moral hazard and adverse selection. Quiggin et al. (1993) contend that
very often it is not possible to empirically distinguish between moral hazard and adverse
selection, however different may be in theoretical terms. Consider the case of a farmer that
defers his planting to learn more about soil-moisture and see whether it is in his interest to
purchase drought insurance. This type of behaviour is illustrative of both moral hazard and
adverse selection. It exhibits adverse selection because insurance is purchased only if a lower
3
yield is expected. It is moral hazard because the decision to defer planting is influenced by the
existence of yield insurance. Moschini and Hennessy (2001) review in detail the problems
related to asymetric information. What this wealth of literature, entirely based on US cases and
data, seems to suggest is that there is disagreement about whether or not asymetric information
pose incentives to increase production. In the following section, we review some of theses
works.
On moral hazard Wright and Hewitt (1990, cited by Moschini and Hennessy, 2001) contend that actual demand
for insurance would be lower than is generally believed, because farmers have many other
cheaper means to control and reduce their risks. In general, insurance is thought to be an
expensive RMI, because policies have to be designed in order to reduce the negative effects of
asymetric information. As a result, in the absence of subsidies insurance would not be attractive
to most farmers. Ramaswami (1993) divide up insurance effects in two: moral hazard effects
and risk reduction effects. The first encourages reductions of input use and by the second the
insuree would seek greater expected revenue. However, there is some ambiguity with regards to
moral hazard effects, because increase-production inputs can be also risk-augmenting. In
general, it is thought that fertilisers are risk-augment inputs, and pesticides risk-reduction inputs.
However, insurance policies include a number of provision and features that are meant to reduce
or eliminate moral hazard, but adding little room for risk reduction effects. In Table 1, we offer
a summary of the main literature results about moral hazard.
On adverse selection Combating adverse selection is paramount to being able to offer specific insurance
policies to relatively homogenous groups of farmers. For this, insurers must count on
objectively discriminatory elements to group agents under homogenous risk levels, and charge
different premia. While the confirmation of moral hazard would lead to the conclusion that
insurance is a decoupled policy, the presence of adverse selection needs not be so. What adverse
selection indicates is the absence of discrimination elements and the unbalance of premia and
indemnities. If adverse-selection provides strong incentives to cultivate marginal land, then
insurance may increase production and for that matter should not qualify as a decoupled policy.
Yet, as Moschini and Hennessy (2001) indicate the Canadian Prairie Farm Assistance Act
(1939) was conceived to grant revenue instability of farmers located in territories to which they
should have never been pushed to occupy. While this may be true in many other countries and
regions, the passage of time since land was converted to agriculture precludes qualifying these
4
historical processes as adverse-selection. This, despite the fact premium must be heavily
subsidised to maintain farmers’ interest. Another important factor related to adverse selection is
the fact that the required groups’ homogeniety to avoid adverse selection depends on farmers’
risk aversion. The more risk-averse, the less reluctant they will be to pay premium above their
individual actuarial fair premium. Table 2 includes a number of studies that have addressed the
problem of adverse selection
In short, the evidence in favour a severe asymetric information problems is dubious and
mostly based on a limited number of US insurance policies (MCPI and APH). The literature
seems to suggest that farmers seem to be compelled to purchase insurance attracted by the
expected results, which are also dependent on the level of insurance attached to the premium
(Just et al. 1999). Makki & Somwaru (2001) show high risk US farmers are more likely to
purchase revenue insurance and higher coverage levels, and that low-risk farmers tend to be
overcharged.
A controversial issue about the role of subsidies in the demand for insurance still
revolves and has not been settled in the literature. (Goodwin 2001, p. 543) finds demand
elasticity for insurance is between -0.24 and -0.20. (Serra, Goodwin and Featherstone 2003, p.
109) show that it has be become less elastic in the US as farmers have turned to larger
coverages, favoured by ARPA (2002) increased subsidisation.
3. The Agricultural Insurance system in Spain Agricultural insurance in Spain dates back to the beginning of the 20th century, but remained
fairly unimportant and underwent various waves of decline and resurgence until 1978. This year
saw the passing of the Agricultural Insurance Act which set the stage for a continuous growth of
agricultural insurance in Spain. The Spanish system is based on a mixed public-private model,
in which farmers’ unions and association do also play a crucial role. Interested readers can learn
a complete description of the Spanish insurance system in OECD and EU reports (OECD, 2001
& European Commission, 2000). In Figure 1, we plot the total liability of agricultural
production, including livestock production, and the ratios of total expenditures in premium
subsidisation over total liability. The graph shows the steady growth of the agricultural
insurance, which now reaches about 30 to 40% of all eligible production. Farmers in Spain can
choose among more than 200 different policies, that provide coverages to all possible crops and
animal production. The system has evolved in the last 20 years to offer a wider menu of
products to a wider range of crops and animal production. Premium are subsidised by the
5
Spanish and Regional goverments in a percentage that range from 20 to 45% of the market
premium. In the period 1980-2004, loss ratios for all policies, experimental policies and viable
policies, were respectively, 99.56%, 114.31% and 82.98% (Agroseguro, 2004), indicating that
the system has grown following sound actuarial criteria.
While Spain has followed a traditional approach to define insurable risks and establish
loss adjustment procedures, fitting with the model of Multiple-peril Crop Insurance. In the last
years, the system has evolved to provide yield insurance, based on individual or zonal records,
for many crops including cereal and winter crops, olive trees and a number of other fruit crops.
Two kinds on index insurance have been used experimentally with different success. The failed
attempt came with a potatoe revenue insurance, based on a price index, offered in seasons 2003
and 2004, which very few farmers purchased. The more succesful example is ‘drought’
insurance available to range livestock growers, which is based on a vegetation index produced
by from satelite images.
4. Model of insurance demand Our model considers the case of a single crop, where both yield and price are stochastic. R,
revenue per hectare, results from a product of yield and price, ypR ~~~ ×= . Both ],[~ ppp∈ and
],[~ yyy ∈ have known probability distribution functions, g(p) and f(y). For the moment, we will
assume that p~ and y~ are independent, but will relax this assumption below. Following Glen et
al. (2005), the pdf of R, h(R), has in principle a closed form as long independence holds and p~
and y~ have defined supports, and takes the following form:
∫=y
pR
dyy
yfyRgRh
/
1)()()( (1)
With insurance, revenue is given by:
{eee
ei yyifypyyp
yyifypR
≤×+−×>×
= ~~~)~(
~~~~ (2)
Where ye is the trigger yield, and pe is the price established to evaluate the indemnity. Profit is
given by sPcR nii +−−= ~~π ; with c, being the crop’s cost; Pn is the net premium; and s is an
agricultural policy subsidy in the form of a direct aid. Insurance net premium, as paid by the
farmer results from Pn=(1+δ)(1-ξ) Pf , where δ is the loading factor; ξ is the insurance subsidy;
and Pf the fair premium, evaluated as follows:
6
∫ −=ey
yeef dyyfyypP )()(
Computing Pf is far from trivial and is not defined for all pdfs3 (see Appendix 1 for the case f(y)
follows a gamma distribution). In the absence of insurance, per hectare profit is scR +−= ~~π .
Farmer’s preferences are modeled with an exponential utility function, exhibing constant
absolute risk aversion preferences, U(π)= 1- e-rπ. Later on we shall discuss and relax this
assumption.
It is further assumed that farmer would purchase insurance if he expects to get utility
gains, which under the expected utility hypothesis implies that )()( ππ EUEU i > . Expected
utility in the case of insurance is given by:
∫∫ +−−−+−−−− −+−=yp
yp
scPRry
y
scPyypri dRRhedyyfeEU n
e
nee )()1()()1()( ][])([π (3) (3)
with γ, being the probabilty of getting a yield below ye. Under no insurance, expected utility is
given by:
∫ +−−−=yp
yp
scRr dRRheEU )()1()( ][π (4)
There are two possible strategies to compare the expected utilities of insurance vs. no
insurance, both taking advantage of the moment generating function as in Colander and
Zilberman (1985). One, that relies on the assumption of independence between y and p, is to use
the result of Glen et al. (2005) and compute the integral to obtain h(R), using equation 1, and get
a closed form of )( iEU π and )(πEU . This strategy is applicable to a limited number of cases,
because the combination of pdfs for y~ and p~ that ensure that function (1) can be integrated is
limited to lognormal-lognormal, and beta-beta.
The alternative strategy is perhaps more restricting but more insightful. It is based on the
assumption that R follows a continuous distribution function which has moment generating
function. Obvious candidates are Gamma, Chi-squre or Normal distributions, but as we shall see
below even assuming either distribution the comparison of expected utilities requires additional
functions. Yet, in the fourth section of the paper we show that for a wide range of pdfs for y~
and p~ -- including Beta, Gamma, Lognormal and Normal -- a gamma distribution fits
statistically well for the resulting R~ .
3 If f(y) is a Beta one has to evaluate a Hypergeometric2F1 function; if it is Gamma a Incomplete Gamma
function; and if it is a Lognormal or Normal, one needs evaluating an Error Function.
7
In the Appendix 1, we show that, if y~ and R~ follow distribution functions with moment generating functions, then )()( ππ EUEU i − >0 if and only if:
0)]1)(([)];([ ')( >−−+− −+− ne
e
rPR
reey
Rry erMGFeyrpLIMGFe ββγ (5)
where
eyγ is the probability of y<ye; Re=peye; β= -Pn-c+s; and β’= -c+s.
stands for Lower Incomplete Moment Generating Function, respectively of
);( eey yrpLIMGF
y~ of order rpe and
upper bounds of ye (see Appendix 1); and MGFR(-r) is the moment generating function of R of
order –r. The first bracketed term is the expected utility resulting from the insurance indemnity,
whereas the second one is the difference between the expected utility without insurance and
insurance resulting from stochastic revenue R~ .
Although condition 5 holds only for any pair of ramdon variables, y~ and R~ , with pdfs
with MGFs, to gain some intuition we focus on the particular case of y~ and R~ following two
Gamma distribution, with parameters (λR, αR) and (λy, αy)4. In Appendix 2, we show that
condition 5 can be transformed to:
)1)(())(,();()'( nen
e
rPReeyyeey
rRPry erMGFyrpPyrpMGFee −−−− −−+−> λαγ β (6)
where P( . ) is a regularized gamma function and takes values between 0 and 1. We discuss this
equation after focusing on the term in the bracketed term. From equation 6, if Pn-β’>0, a
necessary condition but not sufficient condition, for )()( ππ EUEU i − >0 to hold is (proof in
Appendix 2) :
)((Im))( REUEUPREU n >+− (7)
where Im stands for indemnity (Im=pe(ye-y)). Condition 7 is intuitively clear: insurance is
purchased if paying the premium is compensated with the utility gains resulting from the
indemnity scheme. Note, however, that condition 7 is only necessary and is based on the
assumption that Pn-β’>0. If per hectare subsidy, s, is sufficiently high, or premium is intensively
subsidised, then it may be the case that Pn–β’= Pn +c–s<0. In this case, necessary condition 7
no longer holds and equation 6 must hold to ensure that insurance is purchased. If premium is
inexpensive relative to other costs, either because of subsidies or because risk is low, and direct
subsidy is large, then insurance may be purchased even if inequality 7 is reversed. Furthermore,
4 Mean equal to α/λ; variance equal to α/λ2; and moment-generating function of order t equal to 1/(1- t(1/λ))α, for t<λ.
8
if Pn-β’<0, then the exponent of the left-hand-side term in 6 switches from negative to positive.
So the larger the subsidies, the greater the incentives to purchase insurance. In the case s is
relatively larger than Pn +c, insurance would still be purchased even if condition 7 does not hold
or even if the insurance policy is relatively inattractive.
An inspection of condition 6 shows that there are eleven parameters (pe, ye, r, δ, ξ, λy,
αy, λR, αR, c, s) affecting the direction of inequality 6. To investigate the role of these
parameters, we decompose )( iEU π in the indemnity scheme, EU(pe(ye-y)-Pn-c+s), and the
other containing the crop revenues, EU(py-Pn-c+s). Furthermore, since δ and ξ play a similar
role, we will drop the latter from the set of comparative analyses. Also, we grouped c−s in a
single parameter c’.
In table 3 we report the results of the comparative statics results for the EU with
insurance. Two further assumptions were made, namely, y~ follows a gamma distribution with
(λy, αy)=(2.86;5.5); p~ follows a beta distribution B(p,q;pmin,pmax) = B(1.35, 2.0; 0.103;
0.145). Monte Carlo simulations of ypR ~~~ = , with y~ and p~ uncorrelated, produced 5000 data
with which a gamma (λR, αR)=(22.3, 5.045) with p-value 0.92 (based on Chi-square test); and
another 5000 data giving rise to a gamma (λR, αR)=(36.15, 8.85) with p-value 0.96 when
y~ and p~ are correlated with ρ=-0.8.
As Table 3 shows only in 4 out of nine possible cases signs can be established
unambiguously. The reason for getting such poor analytical results is due to the fact that gamma
functions are not symmetric, and that skewness cannot be a priori imposed on stochastic
revenue, R~ . Furthermore, large a per hectare subsidy, s, can reverse the sign of the effect, as it
is in the case for ∂EU(pe(ye-y)-Pn-c+s)/∂r. This explains why the effect of the risk-aversion
coefficient is also undefined.
The previous analysis is limitted for a number of reasons. First, DARA utility functions
are assumed to provide more realistic representations of agents’ preferences than CARA
specifications. Secondly, we have assumed that of y~ and R~ follow Gamma distribution
functions with known parameters, which is certainly a very particular case of more general
specifications. Third, we have assumed a very simplistic insurance policy, in which there are no
deductibles and fair premium is evaluated under the assumption of perfect information. In the
following section, we report some simulation results that relax some of the above assumptions.
And fourth, we have only computed the signs of the partial derivatives of )( iEU π .
9
5. Simulation results
Attempting to gain more insight with numerical analyses, we run a series of Monte-Carlo
simulations with a model that relaxes some of the above assumptions. Instead of CARA, we
assume DARA-CRRA preferences, with U(π)=π1-r/1-r, and five levels of r (0.25, 0.5, 0.75, 1,
1.5); yield follows a Gamma distribution with αy =3.5 and λy=2, representing average yields of
1.925 T/ha; ye=1.925 T/ha (which due to asymetry comes with a γye=0.55); two price
distributions, both following a Beta distribution with the same average 0.12 (1000 € per T) but
with increasingly wider support as shown in Table 4’s first row; that price and yield are
uncorrelated (ρ=0) or negatively correlated (ρ=−0.8). We also assume five levels for (1+λ)(1-
ξ), ranging from ‘very subsidised and/or low loading factor’, (1+λ)(1-ξ)=0.25, to ‘no subsidies
and/or high loading factor’, (1+λ)(1-ξ)=1.5. Cost minus subsidy is set at c−s=1300€ for all
simulations.
Furthermore, in an attempt to gain insight into the role of a miscalculated premium, we
run half of the simulations assuming a correct insurance premium (with Pf=460 €), and half
evaluated as if the premium had been evaluated for a gamma with αy =5.5 and λy=2,86 (with
Pf=390 €). Upon simulation 10,000 ramdon pairs of y and p, we made pairwise comparisons of
)( iEU π and )(πEU using condition (8) obtaining 240 possible comparisons. In Table 4, plus ‘+’
means )( iEU π > )(πEU , and a minus sign ‘−’ means otherwise.
Results confirm that if price and yields are negatively correlated, insuring is the best
strategy for a wider range of assumptions and parameters than if they are independent. This is
because revenue, R~ , is less asymmetric with ρyp=-0.8 than with ρyp=0, as shown in Figure 2.
Secondly, miscalculating the premium is more influential if price and yields are correlated than
if they are uncorrelated. This implies that miscalculated premia may have a larger impact with
crops that are more vulnerable to basis risks, like droughts, which affect market prices. Thirdly,
increasing price risk would be followed by less insuring if prices are uncorrelated with yield. If
they are correlated, price risk does not alter the insuring vs. non-insuring ordering. In a final set
of simulation results, not reported in the table, we confirm that lowering pe or ye by 40% reduces
significantly the demand for insurance for all assumptions and parameters.
6. Data sources and documentation
10
The statistical and econometric analyses use data from the Spanish agricultural insurance system
(ENESA). ENESA’s records include individual farm data from 7 agricultural diverse comarcas
(equivalent to US counties). The complete database includes 55,000 farmers and 11 years (1993-
2003), with a complete characterisation of each farm’s insurance strategy, paid premiums,
premium subsidies, and collected indemnities. Table 5 summarises the main descriptive
elements of each comarca. The database includes a diverse set of crop risks, natural conditions
and kinds of insurance policies. For cereals, farmers can choose among three coverage levels,
ranging from basic coverage including hailstorm and fire risks to individual yield risks. Fruit
growers can choose among two coverage levels. From each farmer and year, records include the
following variables: (1) If purchased any insurance (binary); (2) Crops insured, including
surface (ha), expected yield (kg/ha), total liability (€), paid premium (€), premium subsidies (€),
and the kind of coverage; (3) Indemnities (€) received by crop, coverage and year. Depending
on the comarca, 50% of the farmers purchased any insurance policy between 4 and 6 years
during 1993-2003.
Insurance demand analysis will be pursued along two different strategies, requiring the
computation of different actuarial and behavioral variables. For the first set of analyses, we’ve
generating a number of variables, that we first define and later on explain:
Insurit -- binary (0,1) -- if buys any insurance policy in year t.
Insurance00_03t -- categorical (0,4) -- number of years between 2000 and 2003 where Insur=1
(valid only for t=2003).
Exp_benit – numerical (≥0) – a dimensionless measurement of the expected benefit resulting
from purchasing insurance, computed with the following formula (i farmer, j comarca, k
crop, t year):
∑∑
∑∑−
−
= 1
1
0
0_ t
tiktk
t
tiktk
it
Pmium
IndbenExp if Pmiumikt>0
where Indikt is the indemnity (€) and Pmiumikt is the premium paid (€), net of subsidies,
for crop k and year t. Exp_ben provides an idea of the actual expected benefits in terms
collected indemnities for one euro spent in purchasing insurance policies.
Exp_ben_init– numerical (≥0) – a dimensionless measurement of the inferred expected benefit
resulting from purchasing insurance, computed with the following formula (i farmer, j
comarca, k crop, t year):
11
∑
∑
∑
∑
−
−
−
−−
−
−+
=
kik
kktik
it
kikt
kkjtikt
itit
TInst
LossratTInsInsur
Liab
LossratLiabInsurinbenExp
)()1(
)(__
1
1
1
11
1
if Indikt=0 ∀ kt
ijtijt benExpinbenExp ___ = if Indikt≠0 for any k,t.
where Lossratikt-1 is defined by: ∑∑
∑∑−
−
− = 1
1
1
0
0t
t iijkt
t
t iijkt
kjt
Pmium
IndLossrat ; and represents the loss
ratio of crop k in comarca k; Liabikt-1 represents total liability (€) of insured crop by
farmer i. Tinsik is defined by: ; where Ins_crop∑=
=2003
0
_t
tktik cropInsTins kt=1 if crop k was
insured in year t.
Varijt– numerical (≥0) – is a dimensionless measurement of the dispersion of the insurance
payoffs, evaluated in relative terms, as follows:
∑∑
∑
∑
∑− −
−
−
−−
−
⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢
⎣
⎡
−+=1 1
1
1
11
10
)()1(
)(t
t
kik
kkjtik
it
kikt
kiktikt
ittijt
TInst
DispTInsInsur
Pmium
PmiumDispInsurVar β
where βt is weighing factor with ∑ =t
t t0
1β and 01 tt ββ > if t1>t0;
21
1
11
01
111
0
)(
11
⎥⎥⎦
⎤
⎢⎢⎣
⎡ −
−−−
−= ∑ ∑
∑−
−
−−
−
−−−
t
t j ikt
j iktikt
ikt
iktiktikt Liab
PmiumInd
ttLiabPmiumIndDisp and
21
1
11
01
111
0
)(
11)(
⎥⎥⎦
⎤
⎢⎢⎣
⎡ −
−−−
−= ∑ ∑
∑∑
∑ −
−
−−
−
−−
−
t
t j jkt
j jktjkt
j jkt
j jktjktkjt Liab
PmiumInd
ttLiab
PmiumIndDisp
12
Thirdijt– numerical (≥0) – is a dimensionless measurement of the third moment of the insurance
payoffs, evaluated in relative terms similarly to Varijt, except for the exponents of Dispikt
and Dispkjt-1 which are 3 instead of 2.
We now discuss the meaning of each of the above variables, with a few caveats in mind.
First, our three variables are meant to provide a description of the insurance experience of each
farmer, using his individual records as the main sources of information. Second, only when the
records of a farmer are sparce or limited, we add in the insurance variables of his comarca to
complete the evaluation of the variables. Third, because the three variables are built based on
past recorded data our three variables have more explanatory power for the last years of the
series. So no model insurance demand model will be tested for t<2000. Fourth, the three
variables are indices, meant to provide relative measures of the insurance experience of the
farmer, irrespectively of his farm’s size, cropping patterns, profitability or location.
The first variable, Exp_benit, is a typical loss ratio calculated individually along the
insurance experience of the farmer. If for any given year it is greater than 1, that means that the
farmer collected more indemnities up to year t-1 than the total premium paid up to t-1. Exp_benit
may be 0 if the farmer did not received an indemnity at up to year t-1. If the farmer had not
purchased any insurance premium before year t (with t>2000), then Exp_benit is missing and not
used in the analysis. The fact that Exp_benit=0 does not imply that the expected benefit of
purchasing insurance is zero. So as an alternative formulation, we use the inferred measurement
of expected benefit, Exp_ben_init, which is based on a weighted average of the comarca’s loss
ratios of the crops he has purchased. Neither Exp_benit nor Exp_ben_init are perfect indicators
of the expected returns of purchasing insurance, but our hypothesis is that they may be good
enough to explain farmers’ insurance strategies. Figure 3 plots the histograms of Exp_ben (only
for those greater than 0, which total about 64% of all farms) and Exp_ben_in, both evaluated at
the most recent year 2003. Table 6 reports the statistics of both variables for each comarca. The
median in both cases is below 1 for all observations, and greater than 1 only in the comarca of
Segria using the inferred measure of expected return (Exp_ben_in). This is an indication that
adverse selection may not be significant in all comarcas.
The second and third variables, Varijt and Thirdijt, are by construction different from 0 for
all farmers, irrespectively of their insurance experience. They are meant to provide a sense of
the relative dispersion of the difference between collected indemnities and paid premiums. For
this two variables we are assuming that, if the farmer did not purchase any policy in year t, an
equivalent measurement of the dispersion of payoffs is provided by his comarca’s. Note also
that, due to βt the dispersion of the most recent years up to t ensures that Varijt and Thirdijt are
13
evaluated so that more weight is put in those years. As these two variables are meant to provide
an idea of the dispersion of the whole insurance experience of the farmer, they are evaluated
taking into account the relative importance of each insured crop. Note, however, that Exp_benit
(or Exp_ben_init, for that matter) and variables Varijt and Thirdijt provide a completely different
description of the insurance experience of a farmer. While Exp_benit provides a pure return of
the money spent in purchasing insurance, Varijt and Thirdijt capture the relative dispersion of
the payoffs.
7. Insurance demand models
Two approaches can be followed to estimate insurance demand models, each which its own
variants and assumptions. In the first approach, we only look at the dichotomous choice of
purchasing or not purchasing any insurance policy. In the second approach, we estimate a count
model of the number of years between 2000 and 2003 farmers purchased any insurance.
In the first case, we assume a farmer will purchase any type of insurance in year t if:
)0'Pr()0Pr( >+=> ii xInsur εβ
where the explanatory variables are those defined in the previous section, which are entirely
based on the farmer’s past insurance experience. Variants of this model are estimated as a probit
models5. The major difficulty of this approach is choosing the variable capturing the expected
returns from insuring, namely, choosing an inferred or guessed variable or using the actual
returns based on the farmer’s records. Having no a priori clue of what is appropriate, we base
our choice on the econometric results, models’ predicting accuracy and goodness of fit. Table 7
reports the results for three specifications (Exp_ben_in, Exp_ben and Exp_ben using only
farmers for whom Indikt≠0 for any t). All runs have reasonable good sensitity and specificity
indicators. These in turn are similar within the same models, indicating that both the 1s and the
0s are predicted with similar accuracy. Using either Exp_ben_in or Exp_ben does not change the
insurance demand’s models interpreted as a whole. If we use Exp_ben, only farmers who got an
indemnity in the past, the model fits better and coefficients for this variable are greater.
The three variables capturing the insurance returns are strongly significant, and have
stability across models and time specifications. Farmers seem to respond to their insurance
experience, and the relative profitability of purchasing agricultural insurance.
5 A comparison of logit and probit estimates was carried out, finding very similar coefficients and goodness
of fits. Yet, based on better accuracy on Sensitivity and Specificity for Insur, probit models performed slightly better.
14
In general farmers with loss ratios greater than 1 (Exp_ben>1) are assumed to benefit
from low premium relative to their individual risks. In our database, 48% of the farmers who
have collected an indemnity during the 11-year period belong to this category. The percentage
is 29% if we take into account the 55,500 farmers. Table 8 reports the cofficients for the probit
models run separately for farmers Exp_ben>1 and for Exp_ben<1. Results show that farmers
with Exp_ben<1 are more responsive to the three measurements of insurance returns than those
with Exp_ben>1. This is an indication that farmers which are overcharged in relative terms
respond in lesser extent than those that benefit from low charges.
Insurance demand models can also be estimated as a count models, counting the number
of years that a given farmer decides to purchase any type of insurance policy. This is what we do
in our second approach. The dependent variable is Insurance00_03t, which is evaluated in 2003
and takes on values from 0 (no insurance purchased during 2000 and 2003) to 4 (farmer bought
insurance in all years during 2000-03). The model is estimated as poisson model using the same
explanatory variables used for the probit models. Results are reported on Table 9, together with
the predictions for the dependent variable, Insurance00_03t.
The poisson models have good statistical properties. All coefficientes are consistent
across regressions, and not very different from the probit models. Similarly to these, the models
using actual insurance returns (Exp_ben) perform better than those using the inferred measure as
a explanatory variable (Exp_ben_in). Predicted values for the dependent variable
Insurance00_03t are centered on the observed values, except for the case where
Insurance00_03t=0. In this case the prediction is biased towards 1, but for Insurance00_03t>0
predicted values are within a standard deviation of the actual values.
The role of premium subsidies and changes in the indemnities schemes
The literature on insurance demand is clear about the effect of premium subsidies. If, as all
available evidence overwhelmingly shows, farmers respond to the economic incentives that
agricultural insurance policies provide, they would necessarily respond to changes in the
premium subsidies and to changes in the probability and size of insurance indemnities. Table 10
reports the percentage changes of predicted Insurance00_03t for two of the poisson
specifications reported on Table 9, three levels of Exp_ben (Exp_ben_in) and three levels of
Var. By all measures shown in the table, the largest changes occur when the expected benefits
are lower than 0.5, and for Var<1.5. This means that insurance demand is mostly sensitive to
changes of expected revenue for farmers that have the largest variation of returns and lowest
expected return levels. This is an indication that farmers may show more resposiveness to
15
changes in premium subsidies when their loss ratios are lower and the indemnity scheme more
instable.
8. Summary and conclusions
In this study, we have analysed the demand for agriculture insurance using a theoretical model
and an empirical approach. Our theoretical model shows that agricultural insurance providing
coverage for crop losses is dependent on the premium subsidies and the parameters of the yield
distribution. Since indemnities are generally evaluated as the product of the yield loss and a
fixed price, insurance demand is also dependent on the correlation of yield and price, and on the
density function of revenue. We find that when price and yield are negatively correlated, the
incentives to purchase insurance are greater than if they are uncorrelated. Finally, we show that
under cases of heavily subsidised crops, farmers may benefit from insurance even if the
indemnity scheme is not sufficiently large to compensate for the payment of the premium.
While these results confirm that farmers are attracted to policies with positive expected
results, they show that subsidies, both of premia and originating from farm programs, can
inducce farmers to purchase insurance that has poor returns. For instance, we show that even in
cases of premium misalignments, farmers’ would not respond to asymetric information
incentives unless price risk is sufficiently high and price and yield negatively correlated. Lastly,
we show that, even in a very simple setting, farmers’ insuring strategies depend on a dozen of
number of parameters. Some are specific of the insurance policies available, and some depend
on the price and yields relevant to the grower, in addition to the agent’s risk preferences.
From our empirical analyses, we learnt that Spanish farmers’ insurance strategies can be
explained by their actual and observed individual insurance experience. Three variables
describing the observed economic returns from insurance and its variability are enough to
explain insurance demand patterns found across widely different agricultural conditions.
Noteworthy, the demand parameters are quite stable through time, both using probit specific for
single years and count models for 4-year periods. Our results show that farmers respond not
only to the expected returns of their insuring strategy, but also to the dispersion or variability of
the expected indemnities relative to total paid premium and total liability.
We also developed a few variants of the demand models in order to include in the
analyses the observations related to farmers that, even if they show evidence of being active
insurees, they have never received an indemnity. Using an inferred measurement of the expected
returns, based on each farmer’s regional actuarial records, we could estimate an insurance
demand model lumping togthether farmers with actual records of indemnities and farmers with
16
inferred records of indemnities. Demand models in this case show sharp similarity to those
estimated only with observed data. Again, this implies that farmers repond to the expected
returns inferred from the region’s actuarial results, and to the variability of the region’s relative
indemnity scheme.
Obvious avenues for pursuing further the theoretical work are analyse a choice model of
insurance coverage. Using the moment generating function, one can use discreet distribution
functions as well and compare expected benefits of having a simple crop failure insurance vs. a
yield insurance of the type analysed here. In addition, deductibles can also be integrated in the
model to compare alternative policies that have different indemnity schemes.
In the empirical area, the analyses carried out here are just a small fraction of the issues
that the database invites to look at. We have completely left out promising analyses of the
farmers’ choice of coverage and more crop-specific insuring strategies.
17
References Babcock, B.A., D.A. Hennessy. 1996. Input Demand Under Yield and Revenue Insurance American Journal of Agricultural Economics 78:335-347 Barnett, B.J. 2004. “Agricultural Index Insurance Products: Strengths and Limitations”. Agricultural Outlook Forum 2004 Chambers, R. Insurability and Moral Hazard in Agricultural Insurance Markets. 1989. American Journal of Agricultural Economics 71(3): 604-616 Coble, Keith H., Thomas O. Knight, Rulon D. Pope, Jeffrey R. Williams. 1996. “Modeling Farm-Level Crop Insurance Demand with Panel Data”. American Journal of Agricultural Economics 78: 439-447 Collender, Robert N. and David Zilberman, 1985. Land Allocation Under Uncertainty for Alternative Specifications of Return Distributions. American Journal of Agricultural Economics, Vol. 67, No. 4 (November, 1985), pp. 779-786. Garrido, A., M. Bielza and J.M. Sumpsi. (2002). The impact of crop insurance subsidies on land allocation and production in Spain. OCDE, AGR/CA/APM(2002)16. Glen, A., L.M. Leemis and J. H. Drew. 2004. Computing the Distribution of the Product of Two Continuous Random Variables" Computational Statistics and Data Analysis, Volume 44, Number 3: 451-464. Goodwin, B.K. (1994). “Premium rate determination in the Federal Crop Insurance Program: What do averages have to say about risk?”. Journal of Agricultural and Resource Economics 19:382-395 Hennessy, David A. (1998). “The production effects of agricultural income support policies under uncertainty.” American Journal of Agricultural Economics 80 (1): 46-57 Horowitz, J.K., E. Lichtenerg, 1993. “Insurance, Moral Hazard, and Chemical Use in Agriculture”. American Journal of Agricultural Economics 75(5): 926-935 Just, R.E., L. Calvin (1993). “Adverse selection in US crop insurance: The relationship of farm characteristics to premiums”. Unpublished Manuscript, University of Maryland Just, R.E., L. Calvin, J. Quiggin (1999). “Adverse selection in Crop Insurance: Actuarial and Asymmetric Information Incentives”. American Journal of Agricultural Economics 81: 834-849. Ker, Alan P. and Pat J. McGowan (2000). Weather based Adverse Selection and the U.S. Crop Insurance Program: The Private Insurance Company Perspective. Journal of Agricultural and Resource Economics 25: 386-410 Makki, Shiva S., and Agapi Somwaru (2001). Evidence of Adverse Selection in Crop Insurance Markets,Journal of Risk and Insurance 68(4): 685-708.
18
Mishra, Ashok.K., R. Wesley Nimon, Hisham S. El-Ost. Is moral hazard good for the environment? Revenue insurance and chemical input use. Journal of Environmental Management 74 (2005) 11–20 Moschini, G., D.A. Hennessy. 2001. “Uncertainty, Risk Aversion, and Risk Management for Agricultural Producers”. In Handbook of Agricultural Economics V. 1A (Eds. B.Gardner and G. Rausser). Elsevier Science, 87-154 Quiggin, J., G. Karagiannis, J. Stanton (1993) “Crop Insurance and Crop Production: An Empirical Study of Moral Hazard and Adverse Selection”. Australian Journal of Agricultural Economics 37(2): 95-113 Ramaswami, Bharat, 1993. “Supply Response to Agricultural Insurance: Risk Reduction and Moral Hazard Effects”. American Journal of Agricultural Economics 75: 914-925 Roberts, Michael J. (2004). “Effects of Government Payments on Land Rents, Distribution of Payment Benefits, and Production.” In "Decoupled Payments in a Changing Policy Setting", Agricultural Economic Report 838, ERS, USDA. Serra, T., B.K. Goodwin y A.M. Featherstone, 2003."Modeling Changes in the U.S. Demand for Crop Insurance During the 1990s" Agricultural Finance Review 63(2). Skees, J.R. & M.R. Reed. 1986. Rate Making for Farm-Level Crop Insurance: Implications for Adverse Selection. American Journal of Agricultural Economics 68: 653-659 Smith, Vincent H., Barry K. Goodwin, 1996. “Crop Insurance, Moral Hazard, and Agricultural Chemical Use”. American Journal of Agricultural Economics 76: 428-438 Wu, JJ. (1999). “Crop Insurance, Acreage Decisions, and NonPoint-Source Pollution”. American Journal of Agricultural Economics 81: 305-320.
Appendix 1 Fair premium is evaluated as follows:
∫ ∫−=−=e ey
y
y
yeeeeeef dyyyfpypdyyfyypP )()()( γ
If f(y) follows a gamma distribution with parameters (λ, α), then
[ ] ee
yyeee
y
y
yeeef yEypRdyeypRP )(
)()(1 λ
αλγ
αλγ α
αα
λαα
−+− −
Γ−=
Γ−= ∫
Where E-α(λy) is an exponential integral function. Since , then: ),1()( 1 znzzE n
n −Γ= −
[ ] ey
yeeef yyypRP ),1()()(
11 λαλαλγ ααα
+Γ−Γ
−= −−+
19
[ ] [ ]{ }),1()(),1()()(
1111 yyyyyypRP eeeeeef λαλλαλαλγ ααααα
+Γ−−+Γ−Γ
−= −−+−−+
⎥⎦
⎤⎢⎣
⎡Γ
+Γ−+Γ+=
)(),1(),1(
αλαλα
λγ yypRP ee
eef
Where 0),1(),1( <+Γ−+Γ yye λαλα .
Appendix 2 We start by defining )( iEU π , and then establish the conditions for )()( ππ EUEU i − >0.
∫∫ +−−−+−−−− −+−=yp
yp
scPRry
y
scPyypri dRRhedyyfeEU n
e
nee )()1()()1()( ][])([π
)(1);()( rMGFeyrpLIMGFe R
reey
Rry
e
e−−+−= −+− ββγ (A1)
where
eyγ is the probability of y<ye; β= -Pn-c+s; and Re=peye. With LIMGFy(rpe;ye) we denote a portion of a complete Moment Generating Function of variable y of order rpe, defined only on the limited interval [y, ye], defined as follows:
dyyfeyrpLIMGFe
e
y
y
rypeey )();( ∫= (A2)
The second part of )( iEU π uses the same notation, where MGFR(-r) denotes a standard Moment Generating Function:
dRRherMGFyp
py
rRR )()( ∫ −=− (A3)
The EU under the case of no insurance is defined as:
)(1)()1()( '][ rMGFedRRheEU Rr
yp
py
scRr −−=−= −+−−∫ βπ (A4)
with β’=-c+s. Therefore, )()( ππ EUEU i − >0 holds if and only if:
0)1)(();( ')( >−−+− −+− ne
e
rPR
reey
Rry erMGFeyrpLIMGFe ββγ (A5)
Appendix 3
If y~ and R~ follow gamma distributions with parameters (λR, αR) and (λy, αy), then:
20
∫∫ −−−
Γ=
Γ=
eyye
ye yyey yrpyy
y
y
yrypy
eey dyyedyeye
yrpLIMGF0
)(
y0
1
)()();( αλ
αλαα
αλ
αλ
[ ]
[ ])0,()(,([)][()(
)(,()]([)(
y
0y
yeeyyeyy
y
eyyyey
yrprp
yrprpyy
y
y
eyy
y
αλαλαλ
λαλαλ
αα
ααα
Γ−−Γ−−Γ
=
−Γ−−−Γ
=
−
−
Where function ))(,( eyey rpy −Γ λα is an incomplete gamma function (with property )()0,( yy αα Γ=Γ ). Further algebra leads to:
)])(,()[( eeyyey yrpPrpMGF −= λα
)])(,()[(
1)(
)(,()();( y
eeyyey
y
eeyeyeey
yrpPrpMGF
yrprpMGFyrpLIMGF
−=⎥⎥⎦
⎤
⎢⎢⎣
⎡+
Γ−Γ
−=
λα
αλα
Where P( . ) is a regularized gamma function, and takes values P(αy,0)=0 and P(αy,∞)=1. With the above results, A5 can be expressed as:
{ })1)(())(,();()(' −−+−> −− nen
e
rPReeyyeey
RPrry erMGFyrpPyrpMGFee λαγ β (A6)
Reordering terms and taking logarythms:
)1)(())(,();()'( nen
e
rPReeyyeey
rRPry erMGFyrpPyrpMGFee −−−− −−+−> λαγ β (A7)
⎥⎥⎦
⎤
⎢⎢⎣
⎡ −−+−>−−
−−
e
ne
y
rPReeyyeey
rR
n
erMGFyrpPyrpMGFePr
γλα
β)1)(())(,();(
log)'( (A8)
If β’<0, which is so as long as c>s, the left-hand side of A8 is always negative. Therefore a necessary, but not sufficient condition, for )()( ππ EUEU i − >0 is that term within the log of the right-hand-side be less than 1.
)1)(())(,();( ne
e
rPReeyyeey
rRy erMGFyrpPyrpMGFe −− −−+−> λαγ (A9)
Further algebra allows us to get the sought necessary condition:
)((Im))( REUEUPREU n >+− (A10) Where Im stands for indemnity (Im=pe(ye-y)).
21
Tables Table 1. Studies on agriculural insurance and moral harzard Authors Context and data Moral
Harzard (MH)?
Adverse Selection (AS)?
Type insurance Further comments
Horowitz & Lichtenberg (1993)
400 maize US growers (Probit model)
NO -- MCPI Insurance increase fertilisation usage
Quigging et al. (1993)
535 grain US producers
Yes -- Unable to separate MH and AS
MCPI Farmers purchasing insurance use less variable inputs and have lower expected yields
Smith & Goodwin (1996)
235 wheat Kansas producers (simultaneous equations)
Yes -- MCPI Insuring and fertilisation decisions are taken jointly
Babcock and Hennessy (1996)
Simulation models (Maize Iowa)
Yes -- Yield insurance and revenue insurance
Larger coverages leads to lesser incentives to
Coble et al. (1996)
354 Farms in Kansas (77-90)
Yes -- MPCI Farmers expecting more frequent and small indemnities, more ready to purchase insurance
Wu (1999) 235 Maize growers in Nebraska
Minor Yes MPCI Switching crop mix is more important than moral hazard. In total, production increases
Serra et al. (2003)
1600 Kansas growers (1993-2000)
Yes -- APH Insurance demand more inelastic with larger coverage
Mishra et al. (2005)
865 wheat US producers
Yes -- Revenue and crop insurance
Purchasing revenue insurance reduces nitrogen use, but not pesticides
22
Table 2. Studies on adverse-selection in agricultural insurance Authors Context and data Adverse
Selection (AS)?
Moral Harzard (MH)?
Type insurance Further comments
Skees and Read (1986)
Soybeand and Maize growers Illinois and Kentucky
Yes -- APH Rates may be flawed, because groups were based on expected yields
Goodwin (1994)
2247 Kansas farms
Yes -- APH APH rating assume wrong relationship between expected yield and yield variability
Quiggin et al. (1993),
535 grain US producers
Implied -- Unable to separate MH and AS
MCPI Farmers purchasing insurance use less variable inputs and have lower expected yields
Just et al. (1999)
350 US growers Yes -- APH FCIC rate-making induces high risk growers to purchase insurance because of positive expected revenues
Wu (1999) 235 Maize growers in Nebraska
Yes Minor MPCI Adverse selection is more important than moral hazard.
Ker & McGowan (2000)
Insurance companies (Wheat growers in Texas)
Yes MPCI Adverse selection could boost benefits of insurance firms with public reinsurance
Makki and Somwaru 2001)
Iowa corn farmers in 1997 (11 years of insurance data)
Yes -- MCPI and Revenue insurance
Rating system fails to incorporate each farmer’s risks. Low-risk farmers are overcharged and high-risk farmers undercharged
Barnett (2004)
By implication Yes -- APH Lack of data and precise information in rate-making must have been vulnerable to adverse selection
23
Table 3. Results of comparative statics of the model of insurance demand Parameter )( ei yyEU <π )( ei yyEU >π Total Fair
PremiumPf
pe<0 (if
e
fe p
Py
∂∂
< )
? (otherwise)
<0 ? >0
ye<0 (if
e
fe p
Py
∂∂
< )
? (otherwise)
<0 ? >0
r > 0 (if
0<−
+−−+ey
eyef rp
pRscP
λα
)
? (otherwise)
>0 (if scPr n
R
R −+>+λ
α)
? (otherwise)
?
δ’ <0 <0 <0 λy ? <0 (if p and y, uncorrelated)*
>0 (if p and y, correlated)*? >0
αy ? <0* ? <0 λR 0 <0 <0 αR 0 >0 >0 c’ <0 <0 <0 *Established based on calculus and on Monte-Carlo simulations (@Risk, Palisade) All proofs are available from the authors upon request
24
Table 4. Simulation results of the restricted model (y ∼Gamma[αy =5.5; λy=2.86]) p ∼Beta:
B(p,q; pmax,pmin)
p= q=
pmax= pmin=
1.35 2
0.103 0.145
1.35 2
0.07 0.194
1.35 2
0.103 0.145
1.35 2
0.07 0.194
p and y, uncorrelated ρyp=0 p and y, correlated ρyp = -0.8 Pure premium calculation
(1+λ)(1-ξ)
r # of +
Correct Incorrect Corrrect Incorrect Correct Incorrect Correct Incorrect
0.5 0.25 4 - - - - + + + + 0.75 0.25 1 - - - - - - - +
1 0.25 0 - - - - - - - - 1.25 0.25 0 - - - - - - - - 1.5 0.25 0 - - - - - - - - 0.5 0.5 6 + + - - + + + + 0.75 0.5 3 - - - - - + + +
1 0.5 0 - - - - - - - - 1.25 0.5 0 - - - - - - - - 1.5 0.5 0 - - - - - - - - 0.5 0.75 7 + + - + + + + + 0.75 0.75 4 - - - - + + + +
1 0.75 1 - - - - - - - + 1.25 0.75 0 - - - - - - - - 1.5 0.75 0 - - - - - - - - 0.5 1.001 8 + + + + + + + + 0.75 1.001 6 + + - - + + + +
1 1.001 2 - - - - - + - + 1.25 1.001 0 - - - - - - - - 1.5 1.001 0 - - - - - - - - 0.5 1.25 8 + + + + + + + + 0.75 1.25 8 + + + + + + + +
1 1.25 5 + + - - + + + + 1.25 1.25 1 - - - - - + - - 1.5 1.25 0 - - - - - - - - 0.5 1.5 8 + + + + + + + + 0.75 1.5 8 + + + + + + + +
1 1.5 7 + + - + + + + + 1.25 1.5 4 - + - - + + - + 1.5 1.5 1 - - - - - + - -
# of + out of 30 comparisons
10 11 5 7 13 17 13 17
+ means )( iEU π > )(πEU , - means, )( iEU π )(πEU< .
25
Table 5. Description of the study comarcas and insurance data
Number of years between in which Insur=1 between 1993-
2003 Comarca’s Name
Autonomous Community Main insured crops
No. of farmers Average
1st Quart Median
3rd Quart
Albaida C. Valenciana Fruits, Grapes, Vineyard, Citrus, Vegetables 2,779 6.09 3 5 9
Campiña Andalusia Cereals, Citrus, Cotton, Olive, Sunflower 5,356 5.76 3 5 8
Campos Cast-Leon Cereals, Sugar Beet, Leguminosae 4,490 6.59 4 6 10
Guadalentin Murcia Vegetables, Greenhouse crops, Grapes, Fruits 2,173 4.75 2 4 6
Jucar C. Valenciana Fruits, Citus, Vegetables 20,778 5.94 3 6 8
Mancha Castilla-La Mancha
Vineyards, Vegetables, Cereals 13,313 5.59 2 4 8
Segria Catalonia Fruits, Cereals, Vineyards, cereals 6,681 6.40 3 6 10
Table 6. Reports of Exp_ben and Exp_ben_in for year 2003 (n= 55,470) Exp_ben Exp_ben_in
Comarca Average 1st
Quart Median 3rd Quart Perc 90 Average 1st Quart Median 3rd Quart Perc 90Albaida 0.39 0 0.09 0.51 1.08 0.65 0.38 0.42 0.71 1.20 Campiña 0.84 0 0 1.33 2.92 1.18 0.22 0.46 1.98 2.92 Campos 0.69 0 0.08 0.86 2.09 1.10 0.46 0.86 1.03 2.54 Guadalentin 0.51 0 0 0.74 1.62 0.75 0.26 0.56 1.02 1.62 Jucar 0.82 0 0.23 1.19 2.40 1.20 0.66 0.78 1.49 2.40 Mancha 0.93 0.03 0.65 1.33 2.25 1.10 0.38 0.87 1.35 2.25 Segria 1.25 0 0.68 1.84 3.36 1.66 0.66 1.48 2.16 3.36 All 0.86 0 0.34 1.23 2.43 1.18 0.41 0.81 1.50 2.47 Source: ENESA
26
Table 7. Probit models of insurance demand (dep variable Insur) Model Exp_ben (all) Model Ex_ben_in Model Exp_ben (only >0) Years 2003 2002 2000-03 2003 2002 2000-03 2003 2002 2000-03 Exp_ben 0.126 0.050 0.059 0.265 0.237 0.231 0.007 0.007 0.003 0.009 0.010 0.005 Exp_ben_in 0.205 0.096 0.122 0.008 0.008 0.004 Var 6.174 5.569 5.529 6.713 5.838 5.845 7.641 7.270 7.333 0.113 0.109 0.056 0.116 0.112 0.056 0.137 0.137 0.070 Third 3.373 2.813 2.905 3.813 3.040 3.169 4.398 3.912 4.061 0.101 0.097 0.049 0.103 0.099 0.050 0.116 0.114 0.058 Campiña 0.184 0.213 0.265 0.156 0.192 0.235 -0.174 -0.195 -0.070 0.024 0.024 0.012 0.024 0.024 0.012 0.037 0.038 0.019 Segria 0.147 0.230 0.239 0.071 0.191 0.183 0.076 0.123 0.204 0.022 0.023 0.011 0.023 0.023 0.012 0.027 0.029 0.014 Guadalentin -0.094 0.038 -0.020 -0.089 0.039 -0.020 -0.077 0.074 0.070 0.036 0.035 0.018 0.036 0.036 0.018 0.050 0.051 0.025 Campos 0.031 0.051 0.103 -0.020 0.028 0.074 -0.025 -0.009 0.030 0.017 0.018 0.009 0.018 0.018 0.009 0.023 0.025 0.013 Albaida 0.199 0.233 0.187 0.200 0.235 0.189 0.188 0.285 0.316 0.031 0.031 0.016 0.031 0.031 0.016 0.042 0.044 0.022 Jucar 0.787 0.787 0.796 0.729 0.772 0.773 0.792 0.695 0.764 0.018 0.019 0.009 0.020 0.020 -0.010 0.027 0.030 0.015 Intercept -1.703 -1.668 -1.572 -1.843 -1.736 -1.660 -2.152 -2.283 -2.217 0.018 0.019 0.009 0.020 0.020 -0.010 0.027 0.030 0.015
Sensitivity Pr( +| D) 0.798 0.811 0.792 0.80 0.812 0.7941 0.871 0.881 0.879 Specificity Pr( -|~D) 0.745 0.720 0.705 0.75 0.7258 0.7063 0.716 0.726 0.718 Positive predictive value Pr( D| +) 0.786 0.780 0.777 0.787 0.7838 0.7778 0.818 0.820 0.823 Negative predictive value Pr(~D| -) 0.758 0.757 0.724 0.759 0.7593 0.726 0.791 0.811 0.799 McFadden's R2 0.294 0.288 0.269 0.299 0.289 0.271 0.359 0.379 0.369 No. Obs 52334 49917 195230 52334 49917 195230 32291 28830 111136
All coeficients assymptotically significant at p>0.01 Standard deviations reported in the cells below the coefficients
27
Table 8. Probit models of insurance demand (dep variable Insur) differentiating Exp_ben>1 and Exp_ben<1. Only if Exp_ben>0 &
Exp_ben<1 Only if Exp_ben>0 &
Exp_ben>1 Exp_ben 0.397 0.209 0.0459 0.0139
Var 10.08 7.00 0.316 0.193
Third 6.769 3.926 0.3104 0.162
Sensitivity Pr( +| D) 0.866 0.88 Specificity Pr( -|~D) 0.753 0.68 Positive predictive value Pr( D| +) 0.814 0.83 Negative predictive value Pr(~D| -) 0.82 0.76 McFadden's R2 0.391 0.326 n. Obs 16649 15642 All coeficients assymptotically significant at p>0.01 Standard deviations reported in the cells below the coefficients
28
Table 9. Poisson models of insurance demand (Dependent Variable Insurance00_03)
Model
Exp_ben>0 Model
Exp_ben_in
Model Exp_ben>0 (Loss rat>1)
Model Exp_ben>0 (Loss rat<1)
Exp_ben 0.136 0.108 0.091 0.004 0.006 0.020 Exp_ben_in 0.126 0.004 Var 5.478 5.654 4.349 6.440 0.072 0.061 0.098 0.144 Third 3.265 3.424 2.462 3.895 0.062 0.055 0.080 0.141 Campiña -0.003 0.123 0.069 0.171 0.017 0.012 0.021 0.029 Segria 0.069 0.040 0.062 0.096 0.012 0.011 0.017 0.018 Guadalentin 0.031 -0.028 0.003 0.081 0.024 0.019 0.037 0.031 Campos 0.029 0.000 0.016 0.060 0.010 0.009 0.015 0.014 Albaida 0.164 0.100 0.207 0.168 0.018 0.016 0.038 0.022 Jucar 0.306 0.302 0.297 0.349 0.014 0.011 0.022 0.022 Intercept -0.835 -0.792 -0.562 -1.103 0.014 0.011 0.022 0.022 Pseudo R2 0.229 0.235 0.189 0.271 Log likelihood -49442 -78298 -24814 -24359 n.obs 32151 52192 15505 16646 Predicted Insurance00_03=0 0.872 0.890 1.079 0.720 0.314 0.299 0.328 0.286 Predicted Insurance00_03=1 1.509 1.352 1.703 1.331 0.541 0.526 0.564 0.553 Predicted Insurance00_03=2 1.847 1.624 1.883 1.519 0.785 0.758 0.733 0.815 Predicted Insurance00_03=3 2.585 2.415 2.536 2.241 1.160 1.161 1.082 1.279 Predicted Insurance00_03=4 3.614 3.587 3.589 3.462 1.151 1.193 1.122 1.400
All coeficients assymptotically significant at p>0.01 Standard deviations reported in the cells below the coefficients
29
Table 10. Percent changes of predicted counts based on the expected returns of insurance Exp_ben -- Poisson Model
Var Exp_ben Min-max
0 to 1 change
From ½ below to ½ above base value
From ½ std below to ½ std
above base value
Marginal Effect
>1 0.2658 0.266 0.2658 0.072 0.2656 <1.5 0.5-1 0.1362 0.2635 0.272 0.0391 0.2718 <0.5 1.3509 0.2378 0.2946 0.2738 0.2944 >1 0.2576 0.2578 0.2574 0.0693 0.2572 <1 0.5-1 0.1295 0.2506 0.2586 0.037 0.2584 <0.5 1.1643 0.205 0.2541 0.2421 0.2539 >1 0.1186 0.119 0.1189 0.032 0.1189 <0.5 0.5-1 0.0594 0.115 0.1187 0.017 0.1186 <0.5 0.6777 0.1196 0.1513 0.1548 0.1512 Exp_ben_in Exp_ben_in -- Poisson Model >1 0.2146 0.2148 0.2155 0.0573 0.2154 <1.5 0.5-1 0.1113 0.2158 0.2227 0.027 0.2225 <0.5 1.1312 0.2048 0.2443 0.2057 0.2442 >1 0.2098 0.21 0.2106 0.0559 0.2105 <1 0.5-1 0.1079 0.2092 0.2159 0.026 0.2158 <0.5 1.008 0.1826 0.2171 0.1835 0.217 >1 0.1189 0.1194 0.12 0.0311 0.1199 <0.5 0.5-1 0.0636 0.1234 0.1273 0.0144 0.1272 <0.5 0.6311 0.1146 0.1367 0.1223 0.1366 All marginal effects assymptotically significant p>0.01
30
Figure 1. Total agricultural insurance liability and ratios of Premium subsidies over liability in Spain (1992-2004)
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Year
Mill
ion
Eur
os
0.00%
1.00%
2.00%
3.00%
4.00%
5.00%
6.00%
7.00%
8.00%
9.00%
10.00%
Insured capital
Agric Ins Cap
Subsidies Ratio
Agric Subs ratio
Source: ENESA (2005)
31
Figure 2. Density functions of R with correlated and uncorrelated price and yield
0
0.1
0.2
0.3
0.4
0.5
0.6
-2 -1 0 1 2 3 4 5 6 7 8
CorrelatedUncorrelated
32
Figure 3. Histograms for Exp_ben (when >0) and Exp_ben_in (year 2003) based on Insurance00_03
0.5
1D
ensi
ty
0 1 2 3 4 5Exp_Ben_in
No ins 00-03
0.5
11.
5D
ensi
ty
0 1 2 3 4 5Exp_Ben_in
Twice in 00-03
0.5
11.
5D
ensi
ty
0 1 2 3 4 5Exp_Ben_in
Three in 00-03
0.2
.4.6
.81
Den
sity
0 1 2 3 4 5Exp_Ben_in
All in 00-03
0.2
.4.6
.8D
ensi
ty
0 1 2 3 4 5Exp_Ben
No ins 00-03
0.2
.4.6
Den
sity
0 1 2 3 4 5Exp_Ben
Twice in 00-03
0.2
.4.6
Den
sity
0 1 2 3 4 5Exp_Ben
Three in 00-03
0.2
.4.6
Den
sity
0 1 2 3 4 5Exp_Ben
All in 00-03
Histograms of Exp_ben_in and Exp_ben>0
33