Birth Cohort Size Research Articles

Population Growth, Immigration, and Labor Market Dynamics

This article provides a first synthesis of population flows and labor market dynamics across immigrant and native-born populations. We devise a novel dynamic accounting methodology that integrates population flows from two sources—changes in birth cohort size and immigrant flows—with labor market dynamics. We illustrate the method using data for the United Kingdom, where population flows have been large and cyclical, driven first by the maturation of baby boom cohorts in the 1980s and later by immigration in the 2000s. New measures of labor market flows by migrant status uncover the flow origins of disparities in the levels and cyclicality of immigrant and native labor market outcomes and their more recent convergence. An application of our accounting framework reveals that population flows have played a nontrivial role in the volatility of labor markets among the UK-born and, especially, immigrants.

Birth Cohort Size Variation and the Estimation of Class Size Effects

Birth Cohort Size Variation and the Estimation of Class Size Effects

The Demographic Echo of War and educational attainment in Soviet Russia

Research on Western countries has shown that birth cohort size is negatively related to educational attainment. It has offered complementary interpretations of this association – optimal schooling choices versus cohort overcrowding effects – that are diffi

Fortunes of Dragons: Cohort size effects on life outcomes

This paper examines the long-term effects of birth cohort size on life outcomes. Using administrative data from Singapore, we study the outcomes of large birth cohorts created by the Chinese superstitious practice of zodiac birth timing, where parents prefer to give birth in the year of the Dragon. This practice is followed exclusively by the Chinese majority, with no similar patterns detected among non-Chinese minorities, allowing us to differentiate cohort size effects from confounding year-of-birth effects. Despite government efforts to increase public educational resources for these cohorts, Chinese Dragons earn lower incomes and are less likely to gain admission to national universities. There is also evidence of negative externalities on non-practising populations who happen to enter the labour market at the same time as Chinese Dragons. Our analysis suggests that the adverse life outcomes are not due to selection, but rather reflect the aggregate resource implications of birth cohort size. Supplementary material is available for this article at: https://doi.org/10.1080/00324728.2020.1864458

Fertility, immigration, and lifetime wages under imperfect labor substitution

AbstractThis paper provides new insights into the effect of birth cohort size on cohort lifetime wages and its sensitivity to the future trajectories of immigration and fertility. The main innovation is to relax the typical assumption of perfect substitution of labor by age. The effect of imperfect substitution of labor by age is to qualify the standard result that smaller birth cohorts are likely to enjoy relatively high wages since that result depends on the size of co-worker cohorts. The positive small cohort effect on lifetime wages therefore depends on demographic patterns, which are simulated here through low and high fertility and immigration projections. The analysis applies to actual and projected cohorts for Australia and tests the sensitivity to alternative demographic parameters, and the substitution and discount parameters. The effects of imperfect substitution can amount several percentage points of lifetime wages.

Brazil's Missing Infants: Zika Risk Changes Reproductive Behavior.

Zika virus epidemics have potential large-scale population effects. Controlled studies of mice and nonhuman primates indicate that Zika affects fecundity, raising concerns about miscarriage in human populations. In regions of Brazil, Zika risk peaked months before residents learned about the epidemic and its relation to congenital anomalies. This spatiotemporal variation supports analysis of both biological effects of Zika infection on fertility and the effects of learning about Zika risk on reproductive behavior. Causal inference techniques used with vital statistics indicate that the epidemic caused reductions in birth cohort size of approximately one-quarter 18 months after Zika infection risk peaked but 10 months after public health messages advocated childbearing delay. The evidence is consistent with small but not statistically detectable biological reductions in fecundity, as well as large strategic changes in reproductive behavior to temporally align childbearing with reduced risk to infant health. The behavioral effects are larger for more-educated and older women, which may reflect facilitated access to information and to family planning services within high-risk, mosquito-infested urban locations as well as perceptions about the opportunity costs of risks to pregnancy and infant survival.

Birth Cohort Size Variation and the Estimation of Class Size Effects

Birth Cohort Size Variation and the Estimation of Class Size Effects

Birth Cohort Size Variation and the Estimation of Class Size Effects

We show that in school systems with grade retention or redshirting, birth cohort size is negatively related to the grade-level share of students who are too old for their grade. This compositional effect gives rise to an upward bias in estimates of class size effects based on commonly used research designs exploiting within-school variation in birth cohort size. Using data for all primary schools in one federal state of Germany, we find support for this compositional effect. Correcting for the resulting bias, we find that not only are smaller classes beneficial for test scores, but also for reducing grade repetitions.

Use of the average age ratio method in analyzing age heaping in censuses: The case of China

Based on the methods of the average period age ratio and the average cohort age ratio, this study systematically assesses age heaping or digit preference in all population censuses of China. Our study finds that the overall age heaping was relatively low in the Chinese censuses; however, there was a notable preference for ages ending with zero after age 50 in the first two censuses, despite a weakening trend over time. Our study further shows that age heaping in China’s censuses is likely associated with age-related policies such as those on late marriage and retirement. As shown in the study, the average age ratio method can be an alternative of the Whipple’s Index and be improved if the size of birth cohort was taken into account when the number of births is generally reliable.

Sub-national variation in measles vaccine coverage and outbreak risk: a case study from a 2010 outbreak in Malawi

BackgroundDespite progress towards increasing global vaccination coverage, measles continues to be one of the leading, preventable causes of death among children worldwide. Whether and how to target sub-national areas for vaccination campaigns continues to remain a question. We analyzed three metrics for prioritizing target areas: vaccination coverage, susceptible birth cohort, and the effective reproductive ratio (RE) in the context of the 2010 measles epidemic in Malawi.MethodsUsing case-based surveillance data from the 2010 measles outbreak in Malawi, we estimated vaccination coverage from the proportion of cases reporting with a history of prior vaccination at the district and health facility catchment scale. Health facility catchments were defined as the set of locations closer to a given health facility than to any other. We combined these estimates with regional birth rates to estimate the size of the annual susceptible birth cohort. We also estimated the effective reproductive ratio, RE, at the health facility polygon scale based on the observed rate of exponential increase of the epidemic. We combined these estimates to identify spatial regions that would be of high priority for supplemental vaccination activities.ResultsThe estimated vaccination coverage across all districts was 84%, but ranged from 61 to 99%. We found that 8 districts and 354 health facility catchments had estimated vaccination coverage below 80%. Areas that had highest birth cohort size were frequently large urban centers that had high vaccination coverage. The estimated RE ranged between 1 and 2.56. The ranking of districts and health facility catchments as priority areas varied depending on the measure used.ConclusionsEach metric for prioritization may result in discrete target areas for vaccination campaigns; thus, there are tradeoffs to choosing one metric over another. However, in some cases, certain areas may be prioritized by all three metrics. These areas should be treated with particular concern. Furthermore, the spatial scale at which each metric is calculated impacts the resulting prioritization and should also be considered when prioritizing areas for vaccination campaigns. These methods may be used to allocate effort for prophylactic campaigns or to prioritize response for outbreak response vaccination.

Post-Disaster Fertility: Hurricane Katrina and the Changing Racial Composition of New Orleans.

Large-scale climate events can have enduring effects on population size and composition. Natural disasters affect population fertility through multiple mechanisms, including displacement, demand for children, and reproductive care access. Fertility effects, in turn, influence the size and composition of new birth cohorts, extending the reach of climate events across generations. We study these processes in New Orleans during the decade spanning Hurricane Katrina. We combine census data, ACS data, and vital statistics data to describe fertility in New Orleans and seven comparison cities. Following Katrina, displacement contributed to a 30% decline in birth cohort size. Black fertility fell, and remained 4% below expected values through 2010. By contrast, white fertility increased by 5%. The largest share of births now occurs to white women. These fertility differences-beyond migration-driven population change-generate additional pressure on the renewal of New Orleans as a city in which the black population is substantially smaller in the disaster's wake.

Does size matter? Educational attainment and cohort size

Motivated by education expenditure studies consistently finding that education expenditures per student decrease in cohort size, I investigate the relationship between cohort size and the probability of graduating from upper secondary education. If resources are important for student performance, education expenditure studies suggest that being part of a large cohort is a disadvantage. Using a 24-year panel of Norwegian municipalities, I find a small positive effect of cohort size on the probability of graduation, suggesting that being part of a large cohort is actually beneficial. These results are robust to several checks, including accounting for possible Tiebout sorting across school districts and using birth cohort size as an instrument for cohort size in an IV approach. While the analyses conducted in this paper are unable to shed light on whether reduced spending per student actually hurts student outcomes, they indicate that a potential adverse effect of cohort size, working through educational resources, is not strong enough to offset the beneficial effect of larger cohorts on student performance.

Potential (Mis)match? Marriage Markets Amidst Sociodemographic Change in India, 2005-2050.

We explore the impact of sociodemographic change on marriage patterns in India by examining the hypothetical consequences of applying three sets of marriage pairing propensities-contemporary patterns by age, contemporary patterns by age and education, and changing propensities that allow for greater educational homogamy and reduced educational asymmetries--to future population projections. Future population prospects for India indicate three trends that will impact marriage patterns: (1) female deficit in sex ratios at birth; (2) declining birth cohort size; (3) female educational expansion. Existing literature posits declining marriage rates for men arising from skewed sex ratios at birth (SRBs) in India's population. In addition to skewed SRBs, India's population will experience female educational expansion in the coming decades. Female educational expansion and its impact on marriage patterns must be jointly considered with demographic changes, given educational differences and asymmetries in union formation that exist in India, as across much of the world. We systematize contemporary pairing propensities using data from the 2005-2006 Indian National Family Health Survey and the 2004 Socio-Economic Survey and apply these and the third set of changing propensities to multistate population projections by educational attainment using an iterative longitudinal projection procedure. If today's age patterns of marriage are viewed against age/sex population composition until 2050, men experience declining marriage prevalence. However, when education is included, women--particularly those with higher education--experience a more salient rise in nonmarriage. Significant changes in pairing patterns toward greater levels of educational homogamy and gender symmetry can counteract a marked rise in nonmarriage.

Modeling the national pediatric vaccine stockpile: Supply shortages, health impacts and cost consequences

Pediatric vaccine stockpiles have been in place in the U.S. since 1983 to address the potential disruption in supply of routine pediatric vaccines. Increases in the number of vaccines recommended for pediatric and adolescent patients have increased the cost of stocking and maintaining the stockpile. Based on a spreadsheet-based model ( VacStockpile) we developed, we estimated potential supply shortages of 14 stockpiled vaccines as of August 1, 2008 and its health and financial impacts under various shortage and stockpile scenarios. To illustrate the implications of policy options, we compared “high” to “low” stockpile scenarios. The high stockpile scenario ensures a 6-month vaccine supply to vaccinate all children according to recommended schedules. The low scenario comprised of 50% of the high scenario or existing stocks, whichever is smaller. For each vaccine, we used a weighted average of five shortage scenarios ranging from 0% to 100%, in 25% increments. Demand for each vaccine was based on current distribution or birth cohort size. The probabilities of shortages were based on number of manufacturers, market stability, history of manufacturing problems, and production complexity. CDC contract prices were used to estimate costs. Expert opinion and literature provided estimates of health impacts due to shortages. Applying the probabilities of shortages to all vaccines in a single year, the “low” scenario could cost $600 million, with 376,000 vaccine-preventable cases occurring and 1774 deaths. The “high” scenario could cost $2 billion, with an additional $1.6 billion initial stocking, and result in 7100 vaccine-preventable cases occurring and 508 deaths. Based on the assumptions in the model, there is the potential for large differences in outcomes between the scenarios although some outcomes could potentially be averted with measures such as catch-up campaigns after shortages. Using the VacStockpile policy makers can readily evaluate the implications of assumptions and decide which set of assumptions they wish to use in planning.

The Impact of Cohort Size and Local Labor Market Conditions on Human Capital Accumulation in Europe

Recent studies emphasize the impact of macroeconomic factors on educational attainment. They show that although individual factors like the educational level of one's parents play a decisive role in determining the human capital accumulation of the children, the cohort size as well as the local labor market seem to have a significant impact, too. This paper analyzes the impact of birth cohort size as well as unemployment on educational attainment in Europe using the European Community Household Panel. Estimation results suggest that neither the size of the birth cohort nor the local unemployment rate induces a change in the individual's schooling decision.

Wehr- und Zivildienst in Deutschland: Wer dient, wer nicht? / Basic Militaiy and Alternative Service in Germany: Who Serves, Who Doesn't?

Zusammenfassung Die Ableistung eines Wehr- oder Zivildienstes kann als „Naturalsteuer“ interpretiert werden. Folglich lässt sich die praktizierte Heranziehung zu einem dieser Dienste nach Kriterien der Steuergerechtigkeit beurteilen. Seit Einführung der Wehrpflicht in der Bundesrepublik Deutschland im Jahre 1957 haben nur 40 bis 70 % eines Jahrganges einen Wehr- oder Zivildienst geleistet. Damit gibt es einen beachtlichen Anteil an jungen Männern, die durch ein Nicht-Ziehen Vorteile haben, weil bei ihnen z. B. die implizite Einkommensteuer entfällt, die bei Ableistung eines Wehroder Zivildienstes entsteht. Mit den Mikrodaten des Sozio-oekonomischen Panels (SOEP) wird untersucht, welche makro-strukturellen und individuellen Faktoren eine Heranziehung zu Wehroder Zivildienst beeinflussen. Neben der Jahrgangsstärke und der Zunahme an Kriegsdienstverweigerung hat insbesondere das Bildungsniveau der jungen Männer einen erheblichen Einfluss. So haben Abiturienten jüngerer Geburtskohorten gegenüber Real- und Hauptschulabsolventen eine deutlich höhere Wahrscheinlichkeit, einen Dienst zu leisten. Umgekehrt scheinen Arbeitslose den Dienst als berufliche Chance zu begreifen.

RELATIVE COHORT SIZE AND AGE‐SPECIFIC ARREST RATES: A CONDITIONAL INTERPRETATION OF THE EASTERLIN EFFECT*

The demographic theory formulated by Richard Easterlin (1980) predicts a positive relationship between the relative size of birth cohorts and their rates of criminal offending. Extensive testing of this hypothesis has produced scant support in the literature. Drawing on the emerging conditional interpretation of the Easterlin effect, we propose that the impact of fertility decline on the criminal behavior of the Baby Bust generation may have been suppressed by changes in family structure and racial differences in fertility. Although finding support for this argument, particularly in models explaining property crime, in the final analysis, our research underscores the marginal nature of the Easterlin effect as an explanation of criminal behavior.

Components of period fertility in England and Wales.

SummaryThe method of decomposition is applied to evaluate the role played by fertility and age composition of women at risk in annual fluctuations in the number of legitimate live births in England and Wales during the period 1956–70. The analysis shows that the upward trend in the numbers of births during the period 1956–64 was mainly due to a rise in the level of period fertility and that the downward trend thereafter has been due to a declining trend in fertility alone. The analysis also shows that the size and age distribution of women at risk have strongly affected the size of birth cohorts born since 1964. Such effects have been in the direction of increasing the numbers of births to women under 25 years of age in a period of falling fertility.

The Demographic Characteristics of the Negro Population in the United States

The Negro population of the United States is than the white population. Approximately one-half of all Negroes are under 26.1 years of age, whereas the younger half of the white population includes persons up to 30.2 years (difference 3.9 years). The former of these figures is the median of the non-white population according to the 1950 census; but in previous census returns the non-white median age was practically identical with the Negro median age and we can assume that this is still true. Referring again to this heterogeneous classification used by the census to simplify its tabulations at the cost of providing confused information, it is apparent that both the white and non-white classes of our national population have become constantly older. The absolute differences in median ages between the two classes have remained fairly constant for a long time. In 1880, the median ages were: nonwhite 18.0years; white 21 .4 years difference 3.4 years). The age composition of any population at a particular time is the result of three previous conditions: (1) mortality, as it affects proportions surviving from birth to successive ages, (2) migration, and the age distribution of migrants, and (3) rate of growth, due to excess of births over deaths, as it affects the size of birth cohorts at different times. The last consideration, which is often neglected, can be clarified by a simple observation. Persons in their eighties in the United States today are fewer than those in their forties, in part because only about half as many babies were born during the 1870's as in the larger population during the 1910's. The younger age structure of the non-white population, relative to that of the white population of the United States is, therefore, all the more striking because the slower growth of the former prior to 1930 exerted an influence in the opposite direction. The observed effect is evidence of the combined force of the other two factors affecting age composition: immigration, largely restricted to white migrants, and differential mortality. The trend toward the aging of all racial classes can be attributed both to the slowing down of population growth and to increases in longevity. The precise analysis of the changing influence of these diverse factors on the age composition of different racial classes in our population is a complex task which has not been undertaken by the present writers. Nevertheless, we feel warranted in asserting that further decreases in mortality in all elements of the population, and a further narrowing of the differential in mortality between Negroes and whites will tend to bring about the further aging of both elements and a gradual narrowing of their differences in age structure. Actually differences in age composition between the Negro and white sec-