7
ECONOMETRIC MODELLING OF TIME SERIES RELATIONSHIP BETWEEN FERTILITY AND INCOME FOR THE RUSSIAN POPULATION: METHODOLOGICAL ISSUES Oksana Shubat Anna Bagirova Ural Federal University 620002, Ekaterinburg, Russia Email: [email protected] Email: [email protected] KEYWORDS Regression models, time series, modelling, fertility, income ABSTRACT Finding determinants of demographic processes is a highly topical issue in countries with negative demographic trends. Our research was aimed at studying the relationships between fertility and income indicators in Russia. The period under review was 2000 to 2016. To explore the correlation between the time series, we used the methodology of estimating trend deviation. We applied analytical smoothing to model trends, estimating regression models. To assess the strength of relationship between the time series, we analysed correlation between regressions’ residuals. The results of our analysis showed no relationship between people’s incomes and fertility rates. The research we carried out into time series dynamics did not confirm the results of other studies based on static data. Accordingly, this raises questions about the methodology for analyzing the relationship between dynamic processes with a high volatility of input data. Evidently to receive reliable and stable results, multi- dimensional analysis methods should be integrated into the study of relationships between dynamic time series, including preliminary multi-dimensional data classification. This will enable carrying out analysis on homogenous territorial or temporal segments, which would be more methodologically sound. INTRODUCTION Finding determinants of demographic processes is a highly topical issue in countries with negative demographic trends, including today’s Russia. Birthrates in Russia are significantly below the simple reproduction rate. In Soviet times, the Total Fertility Rate (TFR) reached this level, starting to decline in the 1980s. In 2000, the TFR was at its lowest at 1.195, just 56.9% of the replacement fertility rate. Despite the positive dynamic of the TFR in Russia from 2001, the pace of change is very slow and the potential for growth has been exhausted. The adverse demographic situation in Russia is exacerbated by low life expectancy and high mortality rates. Given these factors, studying demographic processes to seek out determinants and develop robust forecasts is highly topical. Fertility is of utmost importance, since it determines natural population growth. However, this demographic process provokes the most vigorous scientific and political debate in Russia – questions related to fertility determinants and ways to regulate it remain unresolved. The issues of the nature of the relationship between fertility indicators and population income levels have been the subject of scientific research by economists and demographers since the 18th century. The nature of the relationship between fertility and people’s wealth has been evaluated with respect to different research subject groups. The first group compares fertility indicators for territories (countries, regions and so on) with different levels of incomes. For example, figure 1 shows a scatter plot of the relationship between GDP levels and TFR in different countries for 2015 (Fertility rate 2017; GDP per capita 2017). The values on the plot suggest an inverse relationship between these variables. Figure 1: Correlation between GDP per capita and TFR in different countries (Fertility rate 2017; GDP per capita 2017) The second group evaluates families/women with different levels of income within the same region. For example, in their study, Maleva and Sinyavksaya identified that for Russian women, growth in income 0 2 4 6 8 0 50000 100000 Total Fertility Rate GDP per capita, $ Proceedings 32nd European Conference on Modelling and Simulation ©ECMS Lars Nolle, Alexandra Burger, Christoph Tholen, Jens Werner, Jens Wellhausen (Editors) ISBN: 978-0-9932440-6-3/ ISBN: 978-0-9932440-7-0 (CD)

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Page 1: ECONOMETRIC MODELLING OF TIME SERIES ... - scs-europe.net · Stopping short of making sweeping statements about declining fertility due to growing incomes, researchers highlight two

ECONOMETRIC MODELLING OF TIME SERIES RELATIONSHIP

BETWEEN FERTILITY AND INCOME FOR THE RUSSIAN POPULATION:

METHODOLOGICAL ISSUES

Oksana Shubat

Anna Bagirova

Ural Federal University

620002, Ekaterinburg, Russia

Email: [email protected]

Email: [email protected]

KEYWORDS

Regression models, time series, modelling, fertility,

income

ABSTRACT

Finding determinants of demographic processes is a

highly topical issue in countries with negative

demographic trends. Our research was aimed at

studying the relationships between fertility and income

indicators in Russia. The period under review was 2000

to 2016. To explore the correlation between the time

series, we used the methodology of estimating trend

deviation. We applied analytical smoothing to model

trends, estimating regression models. To assess the

strength of relationship between the time series, we

analysed correlation between regressions’ residuals. The

results of our analysis showed no relationship between

people’s incomes and fertility rates. The research we

carried out into time series dynamics did not confirm

the results of other studies based on static data.

Accordingly, this raises questions about the

methodology for analyzing the relationship between

dynamic processes with a high volatility of input data.

Evidently to receive reliable and stable results, multi-

dimensional analysis methods should be integrated into

the study of relationships between dynamic time series,

including preliminary multi-dimensional data

classification. This will enable carrying out analysis on

homogenous territorial or temporal segments, which

would be more methodologically sound.

INTRODUCTION

Finding determinants of demographic processes is a

highly topical issue in countries with negative

demographic trends, including today’s Russia.

Birthrates in Russia are significantly below the simple

reproduction rate. In Soviet times, the Total Fertility

Rate (TFR) reached this level, starting to decline in the

1980s. In 2000, the TFR was at its lowest at 1.195, just

56.9% of the replacement fertility rate. Despite the

positive dynamic of the TFR in Russia from 2001, the

pace of change is very slow and the potential for growth

has been exhausted. The adverse demographic situation

in Russia is exacerbated by low life expectancy and

high mortality rates.

Given these factors, studying demographic processes

to seek out determinants and develop robust forecasts is

highly topical. Fertility is of utmost importance, since it

determines natural population growth. However, this

demographic process provokes the most vigorous

scientific and political debate in Russia – questions

related to fertility determinants and ways to regulate it

remain unresolved.

The issues of the nature of the relationship between

fertility indicators and population income levels have

been the subject of scientific research by economists

and demographers since the 18th century. The nature of

the relationship between fertility and people’s wealth

has been evaluated with respect to different research

subject groups.

The first group compares fertility indicators for

territories (countries, regions and so on) with different

levels of incomes. For example, figure 1 shows a scatter

plot of the relationship between GDP levels and TFR in

different countries for 2015 (Fertility rate 2017; GDP

per capita 2017). The values on the plot suggest an

inverse relationship between these variables.

Figure 1: Correlation between GDP per capita and TFR

in different countries (Fertility rate 2017; GDP per

capita 2017)

The second group evaluates families/women with

different levels of income within the same region. For

example, in their study, Maleva and Sinyavksaya

identified that for Russian women, growth in income

0

2

4

6

8

0 50000 100000

To

tal

Fer

tili

ty R

ate

GDP per capita, $

Proceedings 32nd European Conference on Modelling and Simulation ©ECMS Lars Nolle, Alexandra Burger, Christoph Tholen, Jens Werner, Jens Wellhausen (Editors) ISBN: 978-0-9932440-6-3/ ISBN: 978-0-9932440-7-0 (CD)

Page 2: ECONOMETRIC MODELLING OF TIME SERIES ... - scs-europe.net · Stopping short of making sweeping statements about declining fertility due to growing incomes, researchers highlight two

was accompanied by a decline in the average number of

children per woman (Maleva and Sinyavskaya 2007).

This is shown in Figure 2, presented in decile groups of

women, clustered by income.

Figure 2: Average number of children per woman in

groups of women, clustered by income (Maleva and

Sinyavskaya 2007)

Finally, the third group comprises specific territories

(countries, regions) whose populations display changing

incomes and fertility rates. Recall Adam Smith’s words

that “poverty… seems even to be favourable to

generation” (Smith 1827:33). However, contemporary

researchers are cautious about declaring an adverse

relationship between income levels and birth rates

(Maleva and Sinyavskaya 2007). This is connected to

the fact that, for example, countries with similar

economic dynamics may show varying rates of inverse

fertility dynamics. Moreover, low fertility is observed in

countries with different levels of income across the

population.

Stopping short of making sweeping statements about

declining fertility due to growing incomes, researchers

highlight two reasons for the presumed relationship.

Firstly, as people’s incomes grow, potential parents

start to assign more value to the quality, rather than

quantity, of children. This entails greater investment

(money, work, time) in the quality of children’s human

capital (Lee and Mason 2010; Becker et al. 1990).

Understanding that their resources are finite, parents are

forced to choose between quantity and quality of

children and, in the context of a developed economy,

choose to improve the latter.

The second reason is related to restrictions that

children place upon their parents, first and foremost on

mothers. They are connected to, inter alia, the so-called

“motherhood wage penalty” – a drop in earnings that

follows childbirth. When people’s incomes are high,

this decline becomes more pronounced (Van Bavel

2010; Begall and Mills 2012). Additional adverse

factors include fewer opportunities for professional self-

actualisation and impediments to working mothers’

career development. For countries with developed

economies and high levels of income, these factors

undermine reproductive intentions and consequently

lead to a decline in birth rates.

Despite the fact that such reasons may drive

declining fertility in high-income countries, incentives

that seek to mitigate them are often monetary. In

particular, there is an existing stereotype in

contemporary Russia, that sufficient material resourcing

boosts fertility. This belief led to the introduction of the

so-called maternity capital initiative in 2007, which

seeks to boost income levels and guarantees for women

who decide to have a second child.

As such, despite extensive evidence of a lack of a

positive relationship between income and fertility, in

Russia, economic factors of life continue to be seen as a

key determinant of fertility. This sees the

implementation of corresponding demographic policy

measures, at a high cost to the state.

On the other hand, we believe that such a clearly

mistaken view could hardly have been placed at the

heart of Russia’s demographic policy. One could thus

suppose that the real determinant of fertility is not

economic conditions per se, as the way they are

perceived by people, for instance, through expectations

of future economic and social stability. From this

standpoint, maternity capital, as a way to improve

fertility, may be viewed not as a means of genuine

improvement of material welfare, but attention on the

part of the authorities to family matters and an

orientation towards family values, which in turn raises

people’s confidence in the future and creates certain life

guarantees.

In light of this, our research was aimed at studying

the relationships between fertility and income indicators

in Russia, as well as people’s subjective assessments of

their welfare.

DATA AND METHODS

For our study we used data on annual dynamics for time

series of socio-demographic indicators. The data was

sourced from World Bank and Russian Federal State

Statistics Service resources. The period under review

was 2000 to 2016, which was chosen for two reasons:

firstly, the availability of corresponding open-source

data and secondly, the comparability of indicators as

regards the span of the time series.

The analysis covered the following variables:

- Total Fertility Rate (TFR). The average number of

children that would be born per woman if all women

lived to the end of their childbearing years and bore

children according to a given fertility rate at each age.

TFR is a more direct measure of the level of fertility

than the crude birth rate, since it refers to births per

woman (Total Fertility Rate 2017).

- GDP per capita (constant 2010 US$). Gross

domestic product divided by midyear population. Data

are in constant 2010 U.S. dollars (GDP per capita 2017).

- Consumer confidence index – general, as well as

for women and men separately. A generalised index,

which is calculated on the basis of five individual

indices: past and expected changes to personal material

welfare; past and expected changes to the economic

0

0.4

0.8

1.2

1.6

1 2 3 4 5 6 7 8 9 10

Aver

age

nu

mb

er o

f ch

ild

ren

per

wo

man

Decile groups of women,

clustered by income

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situation in Russia; favourability of conditions for

capital purchases.

These indices are calculated on the basis of data

obtained in the course of representative polls (Consumer

confidence index 2017).

- Coefficient of income differentiation. Characterizes

the degree of social stratification and is defined as a

ratio between the average levels of money income of 10

percent of the population with the highest income and

10 percent of the population with the lowest income

(Coefficient Gini 2017).

- Coefficient Gini – index of income inequality.

Characterizes the level of deviation of the actual volume

of distribution of income of population from the line of

their even distribution. The value of coefficient may

vary from 0 to 1, and the higher the value of the

indicator, the less even is the distribution of income in

the society (Coefficient Gini 2017).

We chose these variables as we sought to include

both objective and subjective indicators of people's

incomes. Objective variables included statistical

indicators of levels and variability of income; subjective

ones covered sociological indicators connected to

people's assessments of the economic situation as a

whole and their material welfare in particular. As such,

we tested three hypotheses in our research:

1. Birth rates are correlated with people's incomes

(in this hypothesis GPD per capita was used as an

objective indicator of people's incomes);

2. Birth rates are correlated with people's subjective

perceptions as regards their income and material welfare

(in this hypothesis the consumer confidence index was

used as the subjective measure of welfare levels);

3. Birth rates are correlated with the level of income

inequality across the population (in this hypothesis, we

used the coefficient of income differentiation and the

index of income inequality as fertility determinants).

To explore the correlation between the time series,

we used two approaches. The first one is the

methodology of estimating trend deviation. We applied

analytical smoothing to model trends, estimating

regression models for the stated time series. We used

Ordinary Least Squares as the method for estimating the

unknown parameters in regression models. To assess the

strength of correlations between the time series, we used

the Pearson correlation (based on a study of correlations

between residuals in regression models). The second

approach entailed assessing a multiple regression

model, where time was one of the explanatory variables.

Including the time variable into the model allowed

assessing the specificity of the influence of income on

the level of fertility, while excluding trend effects.

To test the hypothesis about the possible influence

of income on fertility growth we assessed the models

and tested for a correlation between the studied

variables using synchronized data, and also data about

income levels with one and two-year lags. The idea was

that fertility changes after a change in income, but not

straightaway, with some lag (for example, 1-2 years).

RESULTS

Studying the fertility time series showed that over the

course of the considered period, the growth of this

indicator was well-approximated by a linear trend. The

main results of modelling the total fertility rate trend are

shown in tables 1-2 (model 1). As the presented data

show, the quality of the approximation for the model is

very high with a determination coefficient in excess of

95%. All parameters of the equation are statistically

significant and show that between 2000 and 2016 the

total fertility rate in Russia grew 0.039 points on

average.

Studying GDP per capita dynamics showed that this

dynamic is best approximated by a quadratic function.

Yet the largest part of the initial data (2000-2013) fits

the ascending arc of the parabola, while the three most

recent years (2014-2016) showed a slight decrease in

Russia’s GDP per capita. However we do not consider it

appropriate to speak of an established adverse trend

toward a decline in people’s incomes. The main results

of modeling the trend for GDP per capita are shown in

tables 1-2 (model 2).

Table 1: Model Summary

(dependent variable: model 1 – TFR; model 2 – GDP

per capita)

Mo

del

R S

qu

are

Ad

just

ed R

Sq

uar

e

Std

. E

rro

r

of

the

Est

imat

e

F

Sig

.

1 0.959 0.957 0.042 355.143 0.000

2 0.966 0.961 352.287 197.296 0.000

Table 2: Coefficients

(dependent variable: model 1 – TFR; model 2 – GDP

per capita)

Model

Unstandardized

Coefficients t Sig.

B Std. Error

1 Constant 1.094 0.023 47.145 0.000

Years 0.039 0.002 18.845 0.000

2

Constant 5259.955 289.748 18.154 0.000

Years 819.624 74.103 11.061 0.000

Years^2 -27.474 4.001 -6.866 0.000

Given the growth in both the TFR and income levels

over a long period of time (2000 to 2013), we tested the

hypothesis of an existing correlation between these two

factors in the course of subsequent analysis. During this

period, their dynamics were well approximated by a

Page 4: ECONOMETRIC MODELLING OF TIME SERIES ... - scs-europe.net · Stopping short of making sweeping statements about declining fertility due to growing incomes, researchers highlight two

linear trend; hence we used a multiple linear regression

model. TFR was the dependent variable in the model,

while GDP per capita and time were predictors. The

main parameters of the model are shown in tables 3-4

(model 1). As the presented data show, no relationship

between TFR and GDP per capita was established – the

parameters of the equation were not statistically

significant.

Table 3: Model Summary

(dependent variable: TFR;

predictors: model 1 – GDP per capita;

model 2 – GDP per capita with a 1-year lag;

model 3 – GDP per capita with a 2-years lag)

Mo

del

R S

qu

are

Ad

just

ed R

Sq

uar

e

Std

. E

rro

r

of

the

Est

imat

e

F

Sig

.

1 0.950 0.941 0.041 104.333 0.000

2 0.939 0.928 0.046 84.323 0.000

3 0.937 0.925 0.047 81.463

Table 4: Coefficients

(dependent variable: TFR;

predictors: model 1 – GDP per capita;

model 2 – GDP per capita with a 1-year lag;

model 3 – GDP per capita with a 2-years lag)

Model

Unstandardized

Coefficients t Sig.

B Std. Error

1

Constant 1.338 0.146 9.159 0.000

GDP per

capita

-4.160E-

005 0.000 -1.703 0.117

Years .057 0.011 5.372 0.000

2

Constant 1.183 0.152 7.798 0.000

GDP per

capita

-1.732E-

005 0.000 -.607 0.556

Years .047 0.013 3.592 0.004

3

Constant 1.104 0.144 7.650 0.000

GDP per

capita

-2.428E-

006 0.000 -0.080 0.938

Years .040 0.015 2.783 0.018

Similar analysis with account of a possible lag effect

also did not confirm any correlation (models 2 and 3 in

tables 3-4). An analysis based on a study of the

correlation of residuals in regression models also did not

uncover any relationship between TFR and GPD per

capita in Russia. Pearson correlation coefficients were

not high, nor statistically significant (table 5).

Table 5: Correlations between TFR and GDP per capita

(model 1 – GDP per capita; model 2 – GDP per capita

with a 1-year lag; model 3 – GDP per capita with a 2-

years lag)

Model Indicator Value

1

Pearson Correlation -0.457

Sig. (2-tailed) 0.101

N 14

2

Pearson Correlation -0.180

Sig. (2-tailed) 0.538

N 14

3

Pearson Correlation -0.024

Sig. (2-tailed) 0.935

N 14

To test the hypothesis about the possibility that

people’s subjective perceptions about income and

material welfare influence fertility we studied time

series for consumer confidence indices. We analysed

three indices – general, male and female. The analysis

we carried out showed that between 2000 and 2016

these indices did not show a single development trend.

Until 2007, consumer confidence grew rather stably,

however this gave way to a period of high volatility

with a trend toward sharp decline (figure 3).

Accordingly, given the uninterrupted growth in TFR

throughout this period, the hypothesis about a

correlation between fertility and subjective ideas about

income levels and material welfare was not confirmed.

Figure 3: Dynamic of indices of consumer confidence

for the Russian population

To test the hypothesis about income inequality

possibly affecting fertility we studied time series of the

coefficient of income differentiation and the index of

income inequality. The completed analysis showed that

between 2000 and 2016 both indicators did not have a

single growth trend (figure 4). Thus before 2007 the

level of inequality in people’s income distribution grew,

-30

-20

-10

0

2000 2004 2008 2012 2016

Years

Consumer confidence index (general)

Consumer confidence index (for women)

Consumer confidence index (for men)

Page 5: ECONOMETRIC MODELLING OF TIME SERIES ... - scs-europe.net · Stopping short of making sweeping statements about declining fertility due to growing incomes, researchers highlight two

followed by a short period of stabilization and then

decline. As such, given the uninterrupted growth in TFR

throughout the same period, the hypothesis that fertility

and income inequality are correlated has not been

confirmed.

Figure 4: Dynamics of indicators for income

differentiation of the Russian population

DISCUSSION

The results of our analysis showed no relationship

between people’s incomes and fertility rates. We note

that this is a departure from the results of many other

studies (Maleva and Sinyavskaya 2007; Jones et al.

2011). We believe there could be a number of reasons

behind this.

1. There is considerable differentiation between

Russian regions as regards fertility rates and people’s

incomes. Table 6 presents data from 2016 to illustrate

this variability.

Table 6: Differentiation of incomes and fertility by

Russian regions

Indicators Min Max

Ratio

of max

to min

TFR 1.32 3.35 2.54

Coefficient of income

differentiation 4.7 7.6 1.62

GDP per capita

(rubles) 116007 2047998 17.65

We note that such differentiation is observed over

the entire period we analysed. This highlights an

important methodological problem as regards the

appropriateness of using average values for analysis.

Indeed, given the volatility of input data for income and

fertility that characterize the overall situation in the

country, they can hardly be considered valid indicators.

This in turn may be why similar types of research

(fertility and income, fertility and GPD per capita),

which uses time series of nationwide indicators as

variables, often contradict one another.

One possible way out could be analysis conducted

for a single period but for different regions, or for

groups of people with different incomes. It is worth

noting that the results obtained in different studies of

this kind are also rather contradictory. For instance, the

aforementioned Maleva and Sinyavskaya noted a

negative correlation between income and the number of

children for Russian women (Maleva and Sinyavskaya

2007). At the same time, Konig identified that in

Hungary high earnings strengthened women’s

reproductive intentions (whereas in Germany, for

example, the correlation was much weaker) (Konig

2012). Moreover, analysis carried out using data from a

single period does not lend itself to talking about

reliability of results and their stability over time. In the

end, the situation for a particular year may be

determined by some one-off phenomenon and thus

cannot be seen as confirmation of an established cause-

and-effect relationship. The results of monitoring

research, repeated from time to time using a single

methodology, could provide such confirmation.

However, research of this type is not currently

undertaken in Russia.

It may be that given a high differentiation of

indicators, it would be more appropriate to study

relationships between different socio-economic and

demographic factors across similar types of regions,

rather than for the country as a whole. These regions

could be identified on the basis of, for example, cluster

analysis (using Ward’s method). Regions may be

clustered by income level or TFR, with subsequent time

series analysis inside each typified group. We have

partly used such an approach toward time series analysis

in our previous research (Shubat et al. 2016; Shubat et

al. 2017). The results we obtained, which showed a lack

of relationship between fertility and income, define the

expedience of differentiating groups beforehand. Each

cluster may have its own answer as to whether income

is a determinant of fertility for that group of regions.

2. There may be different determinants when birth

order is taken into account. For example, research by

Wood et al. across seven European countries identified

specific economic and institutional factors that

particularly influence the birth of second children

(Wood et al. 2016); a study by Anna Matysiak and Ivet

Szalma showed that the same demographic policy

measures may have different impact upon the birth of

the first or the second child (Matysiak and Szalma 2014)

and so on.

We believe that variability in determinants for

children of different birth order is even more likely in

Russia. We consider that there is a connection with

demographic policy measures aimed at stimulating

children of a particular birth order. For example, in

2007, Russia introduced financial incentives for second

children – maternity capital (Federal law 256-FZ 2006);

in 2011 and 2012 regions introduced payments for third

children, whereas from 2018 there is a significant

monthly payment aimed at stimulating the birth of first

children (Bill 333958-8 2017).

0.39

0.40

0.41

0.42

0.43

13

14

15

16

17

2000 2004 2008 2012 2016

Index of income inequality

Page 6: ECONOMETRIC MODELLING OF TIME SERIES ... - scs-europe.net · Stopping short of making sweeping statements about declining fertility due to growing incomes, researchers highlight two

Analysing the relationship between people's incomes

and children of different birth order may help to identify

a correlation between income and the birth of children

of specific order. The same could be fairly said for

groups of the population cut by income levels – such

correlations may exist in a specific group/ groups by

income to be levelled out by other determinants.

Unfortunately, this assumption is difficult to verify, as

Russian statistics on birth order are not collected.

3. Subjective, rather than objective factors may have

a greater influence on fertility. It is known that

reproductive behaviour is carried out against a

background of certain stereotypes as regards parenthood

and childbirth, which influence structural elements and

determine social norms on the number of children

(Newson 2005), the approach to parenting (Voroshilova.

2016), ideas about the advantages and disadvantages of

having children for future parents (Bagirova and Shubat

2014) and so on.

Subjective factors may include ideas about family

and children that exist in different religious doctrines.

Given Russia's multi-confessional landscape, this too

may play a significant role. Orthodox Christianity, the

most widespread religion in the country, does not

declare having and raising children as the goal of

marriage. Orthodoxy does not say that parents have to

give children a certain upbringing and education, create

for them cultural, material and social living conditions

that would allow them to flourish in later life.

Meanwhile, having children is encouraged in Islam and

in the Muslim tradition the role of the mother is a

woman's most important, sacred and invested

responsibility.

4. A high “cost of parenting”, which is traditionally

seen as the reason for reduced fertility in developed

countries, manifests itself quite peculiarly in Russia.

This may be due to the fact that unlike developed

countries with a positive correlation between income

and education (for example, this was shown by

Rodriguez-Pose and Tselios (Rodriguez-Pose and

Tselios 2009)), such a correlation began to manifest

weakly only in post-Soviet times. As such, the price of

parenting for developed countries, «paid» by mothers

with a high income and a higher education, is an issue

first of all for mothers with a high level of education,

which is not always backed by high income. In this case

the so-called subjective cost of maternity (unlike the

“objective” “so-called mommy tax, the lost lifetime

income a woman can expect by becoming a mother”

(Crittenden 2010)). This subjectively perceived cost of

motherhood is made up of different components – fewer

opportunities for professional self-actualisation, less

time for leisure, personal development, external

communication and so on. As such, a high “cost of

motherhood” in Russia may be a reason for low fertility

not for women with high income, but for educated

women.

CONCLUSIONS

The research we carried out into time series dynamics

did not confirm the results of other studies based on

static data on the relationship between fertility and

people’s incomes. Accordingly, this raises questions

about the methodology for analyzing the relationship

between dynamic processes with a high volatility of

input data. Evidently to receive reliable and stable

results, multi-dimensional analysis methods should be

integrated into the study of relationships between

dynamic time series, including preliminary multi-

dimensional data classification. This will enable

carrying out analysis on homogenous territorial or

temporal segments, which would be more

methodologically sound.

We note that the demographic policy measures that

are being currently implemented in Russia are

developed based on an assumed relationship between

people’s incomes and fertility. At the same time, there is

no unambiguous confirmation of a cause-and-effect

relationship. Moreover, there may be a different,

inverse, relationship between these indicators: a large

number of children may drive greater professional

engagement due to the need to provide for a family. The

role of latent factors also cannot be ruled out – for

example, the provision of housing, orientation toward

family values and so on, which may vary across

different groups of the population with different income

levels and be connected to fertility rates more than

income levels.

We believe there is opportunity to extend our

research by adapting the methodology for modelling

and carrying out multi-dimensional analysis to study

demographic processes in Russia. This is necessary to

find substantiated answers to questions about real

determinants of fertility in Russia. The search for such

determinants is particularly topical today, when experts

consider the potential for population growth and its

reproductive potential to be exhausted.

ACKNOWLEDGMENTS

The article is processed as one of the outputs of the

research project “Fertility and parenting in Russian

regions: models, invigoration strategies, forecasts“,

supported by the President of Russian Federation,

project no. NSh-3429.2018.6.

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AUTHOR BIOGRAPHIES

OKSANA SHUBAT is an Associate Professor of

Economics at Ural Federal University (Russia). She has

received her PhD in Accounting and Statistics in 2009.

Her research interests include demographic processes,

demographic dynamics and its impact on human

resources development and the development of human

capital (especially at the household-level). Her email

address is: [email protected] and her Web-page can

be found at http://urfu.ru/ru/about/personal-

pages/O.M.Shubat/

ANNA BAGIROVA is a professor of economics and

sociology at Ural Federal University (Russia). Her

research interests include demographical processes and

their determinants. She also explores issues of labour

economics and sociology of labour. She is a doctoral

supervisor and a member of International Sociological

Association. Her email address is: [email protected]

and her Web-page can be found at

http://urfu.ru/ru/about/personal-pages/a.p.bagirova/