Estimation of Some Nonlinear Panel Data Models With Both Time-Varying and Time-Invariant Explanatory Variables

The so-called “fixed effects” approach to the estimation of panel data models suffers from the limitation that it is not possible to estimate the coefficients on explanatory variables that are time-invariant. This is in contrast to a “random effects” approach, which achieves this by making much stronger assumptions on the relationship between the explanatory variables and the individual-specific effect. In a linear model, it is possible to obtain the best of both worlds by making random effects-type assumptions on the time-invariant explanatory variables while maintaining the flexibility of a fixed effects approach when it comes to the time-varying covariates. This article attempts to do the same for some popular nonlinear models.     

Contents of Volume 68

Volume Contents

Contents of Volume 68     

Studiengebühren und Matchingqualität

Zusammenfassung  Obwohl Studiengebühren an staatlichen Universit?ten in einigen Bundesl?ndern in Deutschland bereits eingeführt wurden, ist bislang unklar, ob Studiengebühren als Signalling-und Screening-Instrument Informationsasymmetrien auf Hochschulm?rkten verringern k?nnen. Basierend auf einem Modell von Bac (2002) wird die Studienplatzvergabe als einmaliges, nicht-kooperatives Matching-Spiel modelliert. Entgegen der allgemeinen Vermutung wird deutlich, dass die Einführung von Studiengebühren keinesfalls immer zu einer Verbesserung des Matchings zwischen Studienbewerbern und Universit?ten unterschiedlicher Qualit?t führen muss, selbst eine Verschlechterung ist denkbar. Die Betrachtung realer Bildungssysteme mit variablen Studiengebühren gibt Hinweise darauf, dass sich in der Realit?t tats?chlich unterschiedliche Gleichgewichte unterschiedlicher Effizienz eingestellt haben: W?hrend sich die Bildungssysteme Italiens und Portugals in einem effizienten Separating/Screening-Gleichgewicht befinden dürften, wurde in den Bildungssystemen Spaniens und der Schweiz offenbar ein Separating/Semiscreening-Gleichgewicht erreicht. In Gro?britannien scheint sich hingegen ein Pooling/Nonscreening-Gleichgewicht eingestellt zu haben. Für Deutschland lie?e sich nach Einführung variabler Studiengebühren ein Separating/Semiscreening-oder ein Separating/Screening-Gleichgewicht II erwarten.

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Tuition fees and matching quality

Summary  Even though tuition fees in German public universities are started to be introduced, it is not yet clear in how far they may indeed help to overcome the informational asymmetries in higher education and serve as a signalling and screening device. Based on a model by Bac (2002), we analyze the application process of university applicants to universities and the subsequent allocation of university places as a non-cooperative matching game. Unlike the regular supposition, the introduction of tuition fees may not necessarily enhance, but may also worsen the matching between students and faculties of differing quality. Our empirical analysis of different European systems of higher education reveals that — for the case of economics — the Italian and Portuguese systems seem to be in an efficient separating/screening equilibrium while the higher education systems of Switzerland and Spain are more likely to find themselves in a separating/semiscreening equilibrium. In Great Britain, however, we have evidence of a pooling/nonscreening equilibrium. For Germany, following the introduction of variable tuition fees, we would expect a separating/ semiscreening or separating/screening equilibrium II.

Arbeitsgebiete: International vergleichende Personal-und Organisations?konomik, Bildungs-und Hochschul?konomik     

Welfare state context,female labour-market attachment and childbearing in Germany and Denmark

This study investigates the role of female labour-market attachment and earnings in childbearing progressions in two very different European contexts. By applying event-history techniques to German and Danish register data during 1981–2001, we demonstrate how female earnings relate to first, second and third birth propensities. Our study shows that female earnings are positively associated with first birth fertility in Denmark, while this is not the case in West Germany. We interpret our findings based on the fact that Danish social context and policy encourage women to establish themselves in the labour market before becoming mothers, while the German institutional context during the 1980s and 1990s was not geared towards encouraging maternal employment. For higher-order births, the results are less clearcut. For Denmark we find a slightly positive correlation between female earnings and second-birth fertility, while the association is somewhat negative for third-order births. In Germany, women tend to leave the labour market when becoming mothers. Non-employed mothers have elevated second and, in particular, third-birth rates. For the group of mothers who are employed, we find only a weak association between their earnings and higher-order fertility.     

Economic Uncertainty and Fertility

Sociologists and demographers have long been interested in the role of economic uncertainty in family behavior. Despite the prevailing “bourgeois conviction” that economic uncertainty discourages people from having children, the empirical evidence on this issue is mixed. In this paper, I summarize the recent empirical evidence, and discuss the potential limitations of previous investigations. Among the possible shortcomings of these studies is that many relied exclusively on unemployment as an operational definition of labor market uncertainty. Subjective indicators of economic uncertainty, which measure the individual’s perception of his or her economic situation more directly, often were not available to researchers. Moreover, few of these studies explored group-specific differences in behavior. In this paper, we seek to overcome some of the limitations of these earlier analyses. Based on data from the German Socio-Economic Panel (GSOEP), we study the role of perceived economic uncertainty in transitions to first and higher order births for the period 1990–2013. In addition, we examine how different population subgroups (stratified by education, parity, and age) respond to economic uncertainty.     

Migration and the search for a better way of life: a critical exploration of lifestyle migration

For the past few years, the term 'lifestyle migration' has been used to refer to an increasing number of people who take the decision to migrate based on their belief that there is a more fulfilling way of life available to them elsewhere. Lifestyle migration is thus a growing, disparate phenomenon, with important but little understood implications for both societies and individuals. This article outlines and explores in detail a series of mobilities that have in common relative affluence and this search for a better lifestyle. We attempt to define the limits of the term lifestyle migration, the characteristics of the lifestyle sought, and the place of this form of migration in the contemporary world. In this manner, we map the various migrations that can be considered under this broad rubric, recognising the similarities and differences in their migration trajectories. Further to this, drawing on the sociological literature on lifestyle, we provide an initial theoretical conceptualisation of this phenomenon, attempting to explain its recent escalation in various guises, and investigating the historical, sociological, and individualised conditions that inspire this migration. This article is thus the first step in defining a broader programme for the study of lifestyle migration. We contend that the study of this migration is especially important in the current era given the impact such moves have on places and people at both ends of the migratory chain.