Kin recognition and step-paternal investment: the effect of childhood co-residence duration

Evolutionarily relevant nepotistic kin investment requires reliable kin detection. Evolutionary scholars have argued that childhood co-residence is one of the most important indirect cues for kinship. While childhood co-residence duration has been found to correlate with kin investment in intragenerational studies (i.e., among siblings), intergenerational investigations considering the association between childhood co-residence duration and kin investment have been scarce. Here, we investigate whether the investment of biological and stepfathers is correlated with childhood co-residence duration. We used data from adolescents and adults (aged 17–19, 27–29, and 37–39 years) from the German Panel Analysis of Intimate Relationships and Family Dynamics (Pairfam), wave 2, collected in 2010–2011. Paternal investment was measured as financial and practical help, emotional support, intimacy, and emotional closeness. We found that while stepfathers invested less than biological fathers, both biological and stepfathers’ investments increased with increased childhood co-residence duration in most measures. Financial help correlated with childhood co-residence in stepfathers but not in biological fathers who helped financially more than stepfathers regardless of childhood co-residence duration. Emotional support, intimacy, and emotional closeness were correlated with childhood co-residence in both biological fathers and stepfathers. Practical help did not correlate with co-residence in either father. Thus, our results partially support the hypothesis that childhood co-residence duration serves as a kin detection cue and directs intergenerational altruism.

Will the Paris Accord Accelerate Climate Change?

The 2015 Paris climate accord (Paris Agreement) is meant to control our planet’s rising temperature to limit climate change. But it may be doing the opposite in permitting a slow phase-in of CO2 emission mitigation. The accord asks its 195 national signatories to specify their emission reductions and to raise those contributions over time. However, there is no mechanism to enforce these pledges. This said, the accord puts dirty energy producers on notice that their days are numbered. Unfortunately, this “use it or lose it” message may accelerate the extraction and sale of fossil fuels and, thereby, permanently worsen climate change. Our paper uses a simple OLG model to illustrate this long-noted, highly troubling Green Paradox. Its framework properly treats climate damage as a negative externality imposed by today’s generations on tomorrow’s—an externality that is, in part, irreversible and, if large enough, can tip the climate to a permanently bad state. Our paper shows that delaying abatement can be worse than doing nothing. Indeed, it can make all generations worse off. In contrast, immediate policy action can make all generations better off. Finally, we question the standard use of infinitely lived, single-agent models to determine optimal abatement policy. Intergenerational altruism underlies such models. But its assumption lacks empirical support. Moreover, were such altruism widespread, effective limits on CO 2 emissions would, presumably, already be in place. Unfortunately, optimal abatement prescriptions derived from such models can differ, potentially dramatically, from those actually needed to correct the negative climate externality that today’s generations are imposing on tomorrow’s.

Fertility, migration, and altruism

Migration is a human capital investment in which parents bear costs and children share returns. Therefore, migrants from a population with heterogeneous intergenerational discount rates will self-select on intergenerational altruism. Intergenerational altruism and fertility are arguably linked, therefore immigrants might self-select on eventual fertility. Soviet Jews who migrated to Israel despite high migration costs averaged almost one child more than members of the same birth cohorts who migrated later, at lower cost. Distinguishing selection from treatment effects using mothers' age at migration, selection accounts for most of that difference (the proportion varies with specification), even with controls for religion and religiosity. Selection on fertility may have other explanations, including cultural preservation. To probe, we conduct an alternative empirical test of immigrant selection on altruism, finding that U.S. immigrants spend more time with grandchildren than do natives. Additionally, immigrant self-selection on fertility provides an alternative explanation for Chiswick's (1978, Journal of Political Economy86(5), 897–921) earnings-overtaking result.

Management of air pollution by a system of transferable individual emission permits with overlapping generations.

The purpose of this article is to analyze the effectiveness of a pollution management system through individual permits that are distributed to young people with overlapping generations. From a general equilibrium model, the results show that such a system provides the conditions for optimal pollution management. But because of the non-cooperative behavior of the actors, this policy cannot institute intergenerational altruism. Incentives such as tax or subsidy are needed to get the receiving population to better choose between the physical good whose production satisfies their needs and the quality of the environment that depends on their option to sell the permits to firms or the future generation.