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This study assesses the initial effects of the 2016 Brexit referendum on the mobility of academic scholars to and from the United Kingdom (UK). We leverage bibliometric data from millions of Scopus publications to infer changes in the countries of residence of published researchers by the changes in their institutional affiliations over time. We focus on a selected sample of active and internationally mobile researchers whose movements are traceable for every year between 2013 and 2019 and measure the changes in their migration patterns. Although we do not observe a brain drain following Brexit, we find evidence that scholars' mobility patterns changed after Brexit. Among the active researchers in our sample, their probability of leaving the UK increased by approximately 86% if their academic origin (country of first publication) was an EU country. For scholars with a UK academic origin, their post-Brexit probability of leaving the UK decreased by approximately 14%, and their probability of moving (back) to the UK increased by roughly 65%. Our analysis points to a compositional change in the academic origins of the researchers entering and leaving the UK as one of the first impacts of Brexit on the UK and EU academic workforce., (Copyright © 2024 The Authors.)

A growing body of research shows that demographic attitudes and behaviors across the life course are socially stratified. Building on this and focusing on the transition to parenthood, we hypothesize that (i) parental socioeconomic status is associated with multiple dimensions of the transition to parenthood, including fertility norms (perceived lower age limit at first birth), ideals (ideal age at first birth), and behaviors (age at first birth), and that (ii) this association varies across national contexts, as national contexts determine the opportunities and constraints that guide young adults' life course attitudes and behaviors. Drawing on the European Social Survey 2006 and 2018 data, we analyze early fertility norms and ideals and later fertility behaviors of a pseudo-panel of individuals born between 1976 and 1988. We show that (i) parental socioeconomic status is positively associated with later fertility norms, later fertility ideals, and later childbearing, even when controlling for respondents' own socioeconomic status, and that (ii) national contexts partially moderate these associations. We conclude by discussing implications for theories of fertility and highlighting avenues for future research., Competing Interests: Declarations. Conflict of interest: The authors have no relevant financial or non-financial interests to disclose., (© 2024. The Author(s).)

In 2020, COVID-19-related governmental restrictions forced individuals to radically change their habits, possibly impacting on their living arrangements. Whether COVID-19 affected young adults' propensity to leave the parental home is still unknown; Southern Europe is of particular interest, as youth experience the "latest-late" transition to adulthood, face uncertainty in the labor market, and receive low welfare support. Using EU-SILC longitudinal data from Greece, Spain, Italy, and Portugal, this study examines how home-leaving rates evolved in the short-term and explores the relationship between governmental restrictions, economic characteristics of households and young adults, and leaving home behaviors. Descriptive analyses reveal that the share of young adults leaving the parental home in Southern Europe between 2019 and 2020 slightly increased compared to previous years. Discrete-time event history models show that the propensity to leave the parental home increases with the stringency of policy measures. Young adults with the highest likelihood to leave home are employed individuals whose households are in the lowest income quintile as well as students from the highest income quintile, suggesting that, in these countries, residential independence is associated with either the acquisition of economic resources in the labor market or the availability of family resources. We interpret this result in favor of an "independence effect" exerted by COVID-19-related restrictions on young adults; future research might establish whether this trend is temporary or persistent over time., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Family formation, a process that includes union formation, fertility, and their timing and order, has become increasingly diverse and complex in Europe. We examine how the relationship between socio-economic background and family formation has changed over time in France, Italy, Romania, and Sweden, using first wave Generations and Gender Survey data. Competing Trajectories Analysis, a procedure which combines event-history analysis with sequence analysis, allows us to examine family formation as a process, capturing differences in both the timing of the start of family formation and the pathways that young adults follow. Regarding timing, socio-economic background differences in France and Sweden have remained relatively small, whereas in Italy and Romania higher parental education has become more strongly associated with postponement. Pathways tend to diverge by socio-economic background, particularly in Sweden and France. These results indicate that while family formation patterns have changed, they continue to be stratified by socio-economic background.

Scientific ideas on the human population tend to be rooted in a "slow demography" paradigm, which emphasizes an inertial, predictable, self-contained view of population dynamics, mostly dependent on fertility and mortality. Yet, demography can also move fast. At the country level, it is crucial to empirically assess how fast demography moves by taking migratory movements into account, in addition to fertility and mortality. We discuss these ideas and present new estimates of the speed of population change, that is, country-level population turnover rates, as well as the share of turnover due to migration, for all countries in the world with available data between 1990 and 2020. Population turnover is inversely related to population size and development, and migratory movements tend to become important factors in shaping demography for both small and highly developed countries. Longitudinally, we analyze annual turnover data for Italy and Germany, documenting the changing speed of population change over time and its determinants. Accepting the "fast and slow" demography perspective has several implications for science and policy, which we discuss., (© 2022 The Authors. Population and Development Review published by Wiley Periodicals LLC on behalf of Population Council.)

The Internet has revolutionized our economies, societies, and everyday lives. Many social phenomena are no longer the same as they were in the pre-Internet era: they have been " Internetized ." We define the Internetization of international migration, and we investigate it by exploring the links between the Internet and migration outcomes all along the migration path, from migration intentions to actual migration. Our analyses leverage a number of sources, both at the micro- and the macro-level, including the Gallup World Poll, the Arab Barometer, data from the International Telecommunication Union, the Italian population register, and unique register data from a migrant reception center in Southern Italy. We also distinguish between economic migrants-those who leave their country of origin with the aim of seeking better economic opportunities elsewhere-and political migrants-those who are forced to leave their countries of origin for political or conflict-related reasons. Our findings point to a consistently positive relationship between the diffusion of the Internet, migration intentions, and migration behaviors, supporting the idea that the Internet is not necessarily a driving force of migration per se , but rather an enabling "supportive agent." These associations are particularly relevant for economic migrants, at least for migration intentions. Further analyses underscore the importance of the Internet in providing a key informational channel which helps to define clearer migration trajectories., (© 2020 The Authors. Population and Development Review published by Wiley Periodicals LLC on behalf of Population Council.)

Background: Understanding public perceptions of government responses to COVID-19 may foster improved public cooperation. Trust in government and population risk of exposure may influence public perception of the response. Other population-level characteristics, such as country socio-economic development, COVID-19 morbidity and mortality, and degree of democratic government, may influence perception., Methods and Findings: We developed a novel ten-item instrument that asks respondents to rate key aspects of their government's response to the pandemic (COVID-SCORE). We examined whether the results varied by gender, age group, education level, and monthly income. We also examined the internal and external validity of the index using appropriate predefined variables. To test for dimensionality of the results, we used a principal component analysis (PCA) for the ten survey items. We found that Cronbach's alpha was 0.92 and that the first component of the PCA explained 60% of variance with the remaining factors having eigenvalues below 1, strongly indicating that the tool is both reliable and unidimensional. Based on responses from 13,426 people randomly selected from the general population in 19 countries, the mean national scores ranged from 35.76 (Ecuador) to 80.48 (China) out of a maximum of 100 points. Heterogeneity in responses was observed across age, gender, education and income with the greatest amount of heterogeneity observed between countries. National scores correlated with respondents' reported levels of trust in government and with country-level COVID-19 mortality rates., Conclusions: The COVID-SCORE survey instrument demonstrated satisfactory validity. It may help governments more effectively engage constituents in current and future efforts to control COVID-19. Additional country-specific assessment should be undertaken to measure trends over time and the public perceptions of key aspects of government responses in other countries., Competing Interests: The authors have declared that no competing interests exist.

For billions of people across the globe, mobile phones enable relatively cheap and effective communication, as well as access to information and vital services on health, education, society, and the economy. Drawing on context-specific evidence on the effects of the digital revolution, this study provides empirical support for the idea that mobile phones are a vehicle for sustainable development at the global scale. It does so by assembling a wealth of publicly available macro- and individual-level data, exploring a wide range of demographic and social development outcomes, and leveraging a combination of methodological approaches. Macro-level analyses covering 200+ countries reveal that mobile-phone access is associated with lower gender inequality, higher contraceptive uptake, and lower maternal and child mortality. Individual-level analyses of survey data from sub-Saharan Africa, linked with detailed geospatial information, further show that women who own a mobile phone are better informed about sexual and reproductive health services and empowered to make independent decisions. Payoffs are larger among the least-developed countries and among the most disadvantaged micro-level clusters. Overall, our findings suggest that boosting mobile-phone access and coverage and closing digital divides, particularly among women, can be powerful tools to attain empowerment-related sustainable development goals, in an ultimate effort to enhance population health and well-being and reduce poverty., Competing Interests: The authors declare no competing interest., (Copyright © 2020 the Author(s). Published by PNAS.)

Background: During the transition to adulthood many young adults become obese for the first time in their lives, yet relatively little research has examined why people in this life phase become obese. This study examines what career and family life-course pathways during the transition to adulthood are related to developing obesity in young adulthood., Methods: We use data from the NLSY97, a U.S. nationally representative panel survey conducted by the Bureau of Labor Statistics between 1997 to 2013 (N = 4688), and apply multichannel sequence analysis in order to identify clusters of typical career-family pathways during the transition to adulthood (age 17 to 27), and subsequently investigate whether these pathways are associated with becoming obese at the end of young adulthood (age 28), using logistic regression. We control for obesity at age 17 and family background factors (race, parental education, parental income, and family structure). To take into account the fact that the transition to adulthood has a different meaning for men and for women, we also interact career-family clusters with gender., Results: For women, pathways characterized by college education, early home leaving, and postponement of family formation decrease the probability of becoming obese. For men, pathways characterized by early marriage increase the probability of becoming obese., Conclusions: The results highlight the importance of gender differences in how career and family pathways are related to becoming obese in young adulthood.

The spread of high-speed (broadband) Internet epitomizes the digital revolution. Using German panel data, we test whether the availability of broadband influences fertility choices in a low-fertility setting well known for the difficulty in combining work and family life. We exploit a strategy devised by Falck and colleagues to obtain causal estimates of the impact of broadband on fertility. We find positive effects of broadband availability on the fertility of highly educated women aged 25-45. We further confirm this result using county-level data on total fertility. We show that broadband access significantly increases the share of women reporting home- or part-time working. Furthermore, we find positive effects on time spent with children and overall life satisfaction. Our findings are consistent with the hypothesis that access to broadband allows highly educated women, but not the less educated, to reconcile career and motherhood, which may promote a 'digital divide' in fertility.

Objectives: To document the association between economic development, income inequality, and health-related public infrastructure, and health outcomes among Chinese adults in midlife and older age., Methods: We use a series of multi-level regression models with individual-level baseline data from the China Health and Retirement Longitudinal Survey (CHARLS). Provincial-level data are obtained both from official statistics and from CHARLS itself. Multi-level models are estimated with different subjective and objective health outcomes., Results: Economic growth is associated with better self-rated health, but also with obesity. Better health infrastructure tends to be negatively associated with health outcomes, indicating the likely presence of reverse causality. No supportive evidence is found for the hypothesis that income inequality leads to worse health outcomes., Conclusions: Our study shows that on top of individual characteristics, provincial variations in economic development, income inequality, and health infrastructure are associated with a range of health outcomes for Chinese midlife and older adults. Economic development in China might also bring adverse health outcomes for this age group; as such specific policy responses need to be developed.

We argue that the divergence in fertility trends in advanced societies is influenced by the interaction of long-standing differences in generalized trust with the increase in women's educational attainment. Our argument builds on the idea that trust enhances individuals' and couples' willingness to outsource childcare to outside their extended family. This becomes critically important as women's increased education enhances the demand for combining work and family life. We test our hypothesis using data from the World Values Survey and European Values Study on 36 industrialized countries between the years 1981 and 2009. Multilevel statistical analyses reveal that the interaction between national-level generalized trust and cohort-level women's education is positively associated with completed fertility. As education among women expands, high levels of generalized trust moderate fertility decline.

Despite cohabitation becoming increasingly equivalent to marriage in some of the most 'advanced' Western European societies, the vast majority of people still marry. Why so? Existing theories, mostly based on various approaches tied to cognitive decision-making, do not provide a sufficient explanation of the persistence of marriage. In this article, we argue that feelings attached to marriage, i.e. the affective evaluation of those involved in a partner relationship concerning marriage as opposed to cohabitation, explain the persistent importance of marriage as an institution. We argue that socialization, biological and social-structural factors affect these affective evaluations. We provide a test of our hypotheses using a longitudinal study of young adults in the Netherlands. The results of our analyses are consistent with a central role of feelings in the decision to marry, as well as with a role for key moderating factors such as gender., (© London School of Economics and Political Science 2016.)

Demographers study population change across time and place, and traditionally they place a strong emphasis on a long-range view of population change. This paper builds on current reflections on how to structure the study of population change and proposes a two-stage perspective. The first stage, discovery, focuses on the production of novel evidence at the population level. The second stage, explanation, develops accounts of demographic change and tests how the action and interaction of individuals generate what is discovered in the first stage. This explanatory stage also provides the foundation for the prediction of demographic change. The transformation of micro-level actions and interactions into macro-level population outcomes is identified as a key challenge for the second stage. Specific instances of research are discussed.

This article suggests a procedure to derive stochastic population forecasts adopting an expert-based approach. As in previous work by Billari et al. (2012), experts are required to provide evaluations, in the form of conditional and unconditional scenarios, on summary indicators of the demographic components determining the population evolution: that is, fertility, mortality, and migration. Here, two main purposes are pursued. First, the demographic components are allowed to have some kind of dependence. Second, as a result of the existence of a body of shared information, possible correlations among experts are taken into account. In both cases, the dependence structure is not imposed by the researcher but rather is indirectly derived through the scenarios elicited from the experts. To address these issues, the method is based on a mixture model, within the so-called Supra-Bayesian approach, according to which expert evaluations are treated as data. The derived posterior distribution for the demographic indicators of interest is used as forecasting distribution, and a Markov chain Monte Carlo algorithm is designed to approximate this posterior. This article provides the questionnaire designed by the authors to collect expert opinions. Finally, an application to the forecast of the Italian population from 2010 to 2065 is proposed.

Generalized trust refers to trust in other members of society; it may be distinguished from particularized trust, which corresponds to trust in the family and close friends. An extensive empirical literature has established that generalized trust is an important aspect of civic culture. It has been linked to a variety of positive outcomes at the individual level, such as entrepreneurship, volunteering, self-rated health, and happiness. However, two recent studies have found that it is highly correlated with intelligence, which raises the possibility that the other relationships in which it has been implicated may be spurious. Here we replicate the association between intelligence and generalized trust in a large, nationally representative sample of U.S. adults. We also show that, after adjusting for intelligence, generalized trust continues to be strongly associated with both self-rated health and happiness. In the context of substantial variation across countries, these results bolster the view that generalized trust is a valuable social resource, not only for the individual but for the wider society as well.

This paper provides a review of fertility research in advanced societies, societies in which birth control is the default option. The central aim is to provide a comprehensive review that summarizes how contemporary research has explained ongoing and expected fertility changes across time and space (i.e., cross- and within-country heterogeneity). A secondary aim is to provide an analytical synthesis of the core determinants of fertility, grouping them within the analytical level in which they operate. Determinants are positioned at the individual and/or couple level (micro-level), social relationships and social networks (meso-level); and, by cultural and institutional settings (macro-level). The focus is both on the quantum and on the tempo of fertility, with a particular focus on the postponement of childbearing. The review incorporates both theoretical and empirical contributions, with attention placed on empirically tested research and whether results support or falsify existing theoretical expectations. Attention is also devoted to causality and endogeneity issues. The paper concludes with an outline of the current challenges and opportunities for future research.

Descriptive statistics indicate that civil marriages and marriages preceded by premarital cohabitation are more unstable, i.e., more frequently followed by divorce. However, the literature has shown that selectivity plays an important role in the relationship between premarital cohabitation and union dissolution. We do not have evidence to date regarding the selectivity in the effect of civil marriage. The Italian case appears particularly interesting given the recent diffusion of premarital cohabitation and civil marriage. Using micro-level data from a national-level representative survey conducted in 2003, we develop a multiprocess model that allows unobserved heterogeneity to be correlated across the three decisions (premarital cohabitation, civil marriage, and divorce). Our results show that selectivity is the main factor that explains the higher divorce rates among those who experience premarital cohabitation and a civil marriage. Net of selectivity, the causal effect on union dissolution disappears.

The paper develops and applies an expert-based stochastic population forecasting method, which can also be used to obtain a probabilistic version of scenario-based official forecasts. The full probability distribution of population forecasts is specified by starting from expert opinions on the future development of demographic components. Expert opinions are elicited as conditional on the realization of scenarios, in a two-step (or multiple-step) fashion. The method is applied to develop a stochastic forecast for the Italian population, starting from official scenarios from the Italian National Statistical Office.

Background: This study examines whether social age deadlines exist for childbearing in women and men, how they vary across countries, whether they are lower than actual biological deadlines and whether they are associated with childbearing at later ages and the availability of assisted reproduction techniques (ARTs)., Methods: This study is based on the European Social Survey, Round 3 (2006-2007), which covers 25 countries. Data were gathered on social age deadlines for childbearing in women (21 909 cases) and men (21 239 cases) from samples of representative community-dwelling populations aged 15 and older., Results: Social age deadlines for childbearing were perceived more frequently for women than men. These deadlines are often lower than actual biological limits, and for women and men alike: 57.2% of respondents perceived a maternal social age deadline ≤ 40 years of age; 46.2% of the respondents perceived a paternal social age deadline ≤ 45 years of age. There is also considerable variability in deadlines across countries, as well as within them. At the country level, the presence of social age deadlines for the childbearing of women was negatively associated with birth rates at advanced ages and the prevalence of ART, and later deadlines were positively associated with these factors., Conclusions: It is important to understand the factors that increase and limit late fertility. While biological factors condition fertility, so do social expectations. These findings provide widespread evidence across Europe that social limits exist alongside biological ones, though both sets of factors are more binding for women.

Knowledge of social contact patterns still represents the most critical step for understanding the spread of directly transmitted infections. Data on social contact patterns are, however, expensive to obtain. A major issue is then whether the simulation of synthetic societies might be helpful to reliably reconstruct such data. In this paper, we compute a variety of synthetic age-specific contact matrices through simulation of a simple individual-based model (IBM). The model is informed by Italian Time Use data and routine socio-demographic data (e.g., school and workplace attendance, household structure, etc.). The model is named "Little Italy" because each artificial agent is a clone of a real person. In other words, each agent's daily diary is the one observed in a corresponding real individual sampled in the Italian Time Use Survey. We also generated contact matrices from the socio-demographic model underlying the Italian IBM for pandemic prediction. These synthetic matrices are then validated against recently collected Italian serological data for Varicella (VZV) and ParvoVirus (B19). Their performance in fitting sero-profiles are compared with other matrices available for Italy, such as the Polymod matrix. Synthetic matrices show the same qualitative features of the ones estimated from sample surveys: for example, strong assortativeness and the presence of super- and sub-diagonal stripes related to contacts between parents and children. Once validated against serological data, Little Italy matrices fit worse than the Polymod one for VZV, but better than concurrent matrices for B19. This is the first occasion where synthetic contact matrices are systematically compared with real ones, and validated against epidemiological data. The results suggest that simple, carefully designed, synthetic matrices can provide a fruitful complementary approach to questionnaire-based matrices. The paper also supports the idea that, depending on the transmissibility level of the infection, either the number of different contacts, or repeated exposure, may be the key factor for transmission.

During the twentieth century, the global population has gone through unprecedented increases in economic and social development that coincided with substantial declines in human fertility and population growth rates. The negative association of fertility with economic and social development has therefore become one of the most solidly established and generally accepted empirical regularities in the social sciences. As a result of this close connection between development and fertility decline, more than half of the global population now lives in regions with below-replacement fertility (less than 2.1 children per woman). In many highly developed countries, the trend towards low fertility has also been deemed irreversible. Rapid population ageing, and in some cases the prospect of significant population decline, have therefore become a central socioeconomic concern and policy challenge. Here we show, using new cross-sectional and longitudinal analyses of the total fertility rate and the human development index (HDI), a fundamental change in the well-established negative relationship between fertility and development as the global population entered the twenty-first century. Although development continues to promote fertility decline at low and medium HDI levels, our analyses show that at advanced HDI levels, further development can reverse the declining trend in fertility. The previously negative development-fertility relationship has become J-shaped, with the HDI being positively associated with fertility among highly developed countries. This reversal of fertility decline as a result of continued economic and social development has the potential to slow the rates of population ageing, thereby ameliorating the social and economic problems that have been associated with the emergence and persistence of very low fertility.

Social contact patterns are a critical explanatory factor of the spread of close-contact infectious agents. Both indirect (via observed epidemiologic data) and direct (via diaries that record at-risk events) approaches to the measurement of contacts by age have been proposed in the literature. In this paper, the authors discuss the possibilities offered by time-use surveys to measure contact patterns and to explain observed seroprevalence profiles. The authors first develop a methodology to estimate time-of-exposure matrices, and then they apply it to time-use data for the United States (1987-2003). Finally, the authors estimate age-specific transmission parameters for varicella, commonly known as "chickenpox," from age-specific time-of-exposure and seroprevalence data (United States, 1988-1994). The estimated time-of-exposure matrix reveals a strong element of assortativeness by age. In addition, there are peaks of exposure between people who were born one generation apart (i.e., parents and their children). Models based on the estimated age-specific transmission parameters fit the observed patterns of infection of endemically circulating varicella in a satisfactory way. The availability of time-use data for a large number of countries and their potential to supplement contact surveys make the methods developed extremely valuable and suitable for implementation in several different contexts.

The purpose of this study was to examine the impact of the family of origin on whether migrant and Dutch young adults live in the parental home. Using a sample of 1,678 young adults aged between 15 and 30 years from 847 families with five different ethnic backgrounds, we identified patterns of co-residence and investigated how and to what extent the likelihood of co-residence was influenced by migrant background, family ties, and the socio-economic characteristics of the family. The results show that of the four migrant groups, only Moroccan young adults are more likely than those of Dutch origin to live with their parents. For both migrant and Dutch young adults, family ties and the socio-economic characteristics of the family rather than an ethnic factor are the major influences on living arrangements.

This article studies the association between social norms and the timing of leaving home. Although largely overlooked by most recent studies on leaving home, life-course theory suggests that age norms and age grading influence life-course decisions in general and leaving home in particular. We use Fishbein and Ajzen's model of "reasoned behavior" to integrate this strand of research with the more individualistic view that dominates current thinking. Using data from a Dutch panel survey, we use a Cox regression model with a control for sample selection to estimate the association between perceived age norms and the timing of leaving home. We show that perceived opinions of parents are associated with the actual timing of leaving the parental home but that societal norms and friends' norms concerning the timing of leaving home are not. In addition, the timing of leaving home is also associated with the perceived costs and benefits of leaving home and with the perceived housing market situation.

We use survey data from Bulgaria and Hungary to investigate the determinants of whether women intend to have a first or a second child and, if so, whether they intend to have the child within the ensuing 2 years or later. These determinants differ significantly by the order and timing of the intended birth. The variables used include measures of anomie and social capital and these appear to be among the factors that determine both whether to have a child and when. There is some evidence that these measures and economic factors are relatively more important in Bulgaria than in Hungary, and that ideational factors are more important in Hungary, particularly in the case of voluntary childlessness.

The distribution of age at first marriage shows well-known strong regularities across many countries and recent historical periods. We accounted for these patterns by developing agent-based models that simulate the aggregate behavior of individuals who are searching for marriage partners. Past models assumed fully rational agents with complete knowledge of the marriage market; our simulated agents used psychologically plausible simple heuristic mate search rules that adjust aspiration levels on the basis of a sequence of encounters with potential partners. Substantial individual variation must be included in the models to account for the demographically observed age-at-marriage patterns.

In this paper we conduct descriptive aggregate analyses to revisit the relationship of low and lowest-low period fertility to cohort fertility and key fertility-related behaviour such as leaving the parental home, marriage, and women's labour force participation. Our analyses show that the cross-country correlations in Europe between total fertility and the total first marriage rate, the proportion of extramarital births, and the labour force participation of women reversed during the period from 1975 to 1999. By the end of the 1990s there was also no longer evidence that divorce levels were negatively associated with fertility levels. We argue that lowest-low fertility has been particularly associated with a 'falling behind' of cohort fertility at higher birth orders and later ages. From these analyses we conclude that the emergence of lowest-low fertility during the 1990s was accompanied by a disruption or even a reversal of many well-known relationships that have been used to explain cross-country differences in fertility patterns.

Several studies have explored the impact of marital bereavement on mortality, while increasing emphasis has recently been placed on genetic factors influencing longevity - in this paper, we study the impact of losing the spouse and losing the co-twin, for twins aged 50 to 70. We use data from the Danish Twin Registry and the Population Register of Denmark for the period 1968 through 1999. Firstly, we use survival analysis to study mortality after the death of the spouse or the co-twin. We find that the risk of dying is highest in the first year after the death of the spouse, as well as in the second year after the death of the co-twin. We then use event history analysis techniques to show that there is a strong impact of the event 'losing the co-twin' even after controlling for age, sex and zygosity and that this effect is significantly higher in the second year of bereavement. The effect is similar for men and women, and it is higher for monozygotic twins. The latter confirms the influence of genetic factors on survival, while the mortality trajectory with a peak in the second year after the death of the co-twin is consistent with the existence of a twin bereavement effect.