The effect of multiple paternity on genetic diversity during and after colonisation

In metapopulations, genetic variation of local populations is influenced by the genetic content of the founders, and of migrants following establishment. We analyse the effect of multiple paternity on genetic diversity using a model in which the highly promiscuous marine snail Littorina saxatilis expands from a mainland to colonise initially empty islands of an archipelago. Migrant females carry a large number of eggs fertilised by 1 - 10 mates. We quantify the genetic diversity of the population in terms of its heterozygosity: initially during the transient colonisation process, and at long times when the population has reached an equilibrium state with migration. During colonisation, multiple paternity increases the heterozygosity by 10 - 300 % in comparison with the case of single paternity. The equilibrium state, by contrast, is less strongly affected: multiple paternity gives rise to 10 - 50 % higher heterozygosity compared with single paternity. Further we find that far from the mainland, new mutations spreading from the mainland cause bursts of high genetic diversity separated by long periods of low diversity. This effect is boosted by multiple paternity. We conclude that multiple paternity facilitates colonisation and maintenance of small populations, whether or not this is the main cause for the evolution of extreme promiscuity in Littorina saxatilis.Comment: 7 pages, 5 figures, electronic supplementary materia

Divergent trends in U.S. maternity and paternity leave, 1994–2015

OBJECTIVES: The objective is to determine the number and type of U.S. workers taking maternity or paternity leave. METHODS: This research analyzes secondary data from 1994 to 2015 from the Current Population Survey (CPS). The CPS surveys about 60,000 randomly selected households monthly and provides a publicly available ecological long-term series for measuring parental leave. RESULTS: The average month from 1994 to 2015 saw 273,000 women and 13,000 men on maternity or paternity leave. Maternity leave figures show no trend over 22 years. Paternity figures increase by a factor of three, but start from a small base. No national impact on maternity or paternity leave was observed after implementation of state laws which provided paid leave. About half (51.1%) of employees on maternity or paternity leave during 2015 received paid time off. The typical woman on maternity leave was older, more likely married, more likely white non-Hispanic and more educated than the typical woman who gave birth. CONCLUSION: While the US economy expanded dramatically since 1994, this improvement does not appear to have translated into more women taking maternity leave.  Accepted manuscrip

Causal Effects of Paternity Leave on Children and Parents

In this paper we use a parental leave reform directed towards fathers to identify the causal effects of paternity leave on children’s and parents’ outcomes. We document that paternity leave causes fathers to become more important for children’s cognitive skills. School performance at age 16 increases for children whose father is relatively higher educated than the mother. We find no evidence that fathers’ earnings and work hours are affected by paternity leave. Contrary to expectation, mothers’ labor market outcomes are adversely affected by paternity leave. Our findings do therefore not suggest that paternity leave shifts the gender balance at home in a way that increases mothers’ time and/or effort spent at market work.parental leave, labor supply, child development

Multiple paternity and hybridization in two smooth-hound sharks

Multiple paternity appears to be a common trait of elasmobranch mating systems, with its occurrence likely driven by convenience, due to females seeking to minimize the stress of male harassment. Here we use molecular markers to analyse the frequency of multiple paternity in two related viviparous sharks, Mustelus mustelus and Mustelus punctulatus. We first applied molecular methods to assign pregnant females, embryos and additional reference adults (N\u2009=\u2009792) to one of the two species. Paternity analysis was performed using a total of 9 polymorphic microsatellites on 19 females and 204 embryos of M. mustelus, and on 13 females and 303 embryos of M. punctulatus. Multiple paternity occurs in both species, with 47% of M. mustelus and 54% of M. punctulatus litters sired by at least two fathers. Female fecundity is not influenced by multiple mating and in 56% of polyandrous litters paternity is skewed, with one male siring most of the pups. Genetic analyses also revealed hybridization between the two species, with a M. punctulatus female bearing pups sired by a M. mustelus male. The frequency of polyandrous litters in these species is consistent with aspects of their reproductive biology, such as synchronous ovulation and possible occurrence of breeding aggregations

Daddy Issues: Why Do Swedish Fathers Claim Paternity Leave at Higher Rates than French Fathers?

The development of paid parental leave programs has become a growing part of national and international dialogues. In particular, the implementation of paternity leave is believed to facilitate women’s participation in the workforce, which most Western countries have outlined as an objective. In addition, paternity leave programs are also believed to foster more equitable work environments and challenge gender norms that stereotype women as the primary caregiver. As of 2016, about two-thirds of OECD countries provide some form of both paid maternity, paternity, and combined parental leave ; however, the gender composition of who claims these benefits is still largely skewed in several countries. In France, which has the most elaborate leave system, only 62-66% eligible French fathers take at least part of their offered paternity leave. Furthermore, French fathers only account for 4% of parents who claim parental leave. In Sweden, on the other hand, around 90% of eligible Swedish fathers take at least part of their offered paternity leave, and they account for anywhere from 27 to 45% of parents who claim parental leave. A comparative analysis of five different independent variables - Financial Considerations, Fears of Negative Career Consequences, Breadth and Depth of Maternity Leave, Disinterest, and the Use-it-or-lose is policy - was conducted to determine why French fathers participate in paternity and parental leave programs at significantly lower rates than Swedish fathers. The study concludes that Disinterest, stemming from traditional views on gender roles, is likely the most impactful variable on participation rates. However, Financial Considerations, Fears of Negative Career Consequences, and France’s only recently implemented Use-it-or-lose parental leave policy likely exaggerate this disparity. To further investigate this claim, it would be beneficial to more closely examine and compare French and Swedish workplace cultures as well as how each country’s religious influence impacts the populations’ perceptions of gender roles

The Impact of Paternity Leave on Long-term Father Involvement

Using Norwegian registry data we investigate how paternity leave affects fathers’ long-term earnings. In 1993 Norway introduced a paternity quota of the paid parental leave. We estimate a difference-in-differences model which exploits differences in fathers' exposure to the paternity quota. Our analysis suggests that four weeks paternity leave during the child’s first year decreases fathers’ future earnings by 2.1 percent. Importantly, this effect persists up until our last point of observation when the child is five years old. The earnings effect is consistent with increased long-term father involvement, as fathers shift time and effort from market to home production. In an investigation of Norwegian time use data we find additional evidence for this hypothesis.father involvement, household production, parental leave

Getting Time Off: Access to Leave Among Working Parents

"Mommy, I don't feel good." "Honey, it's time to go to the hospital." When working parents, or parents-to-be, hear these phrases, their anxiety levels often increase. Not only because their children are sick or their partners are in labor, but also because they will have to find a way to keep their jobs while tending to their families' needs. Maternity and paternity leave, along with vacation, sick leave, and personal leave, help workers balance their responsibilities at home and at the office. This brief uses new data from the National Survey of America's Families (NSAF) to portray which working parents have access to paid and maternity/paternity leave.Although federal law guarantees job-protected, unpaid family leave to many workers, only three in five American workers are eligible to take this leave (Cantor et al. 2001). Moreover, no state or federal legislation requires employers to provide paid leave of any kind. Because access to leave is not universal, some caregivers do not fully realize the benefits of job-protected leave, namely job security and some flexibility to care for children.This analysis examines whether access to leave differs by socioeconomic characteristics. The data suggest that the majority of working parents can take maternity or paternity leave from their jobs. Although access to maternity/paternity leave varies with measures of economic well-being, it is much more equal than access to paid leave. Most poor workers, working welfare recipients, and working recent welfare leavers cannot take paid leave from their jobs. And those who can take paid leave typically have fewer days of paid leave than nonpoor workers or workers with no recent welfare experience. The relatively even distribution of access to maternity and paternity leave, compared with the uneven access to paid leave, could be an effect of the Family and Medical Leave Act of 1993 (FMLA)

Patrilocal Exogamy as a Monitoring Mechanism : How Inheritance and Residence Patterns Co-evolve

Economists have modeled inheritance norms assuming the pattern of post-marital residence is exogenous. We model the co-evolution of these two institutions, examining how patrilineal inheritance and patrilocal exogamy reinforced each other in a patrilineal-patrilocal equilibrium. We also derive conditions for a matrilineal-matrilocal equilibrium. The endogenous choice of the old to monitor the sexual behavior of the young women who reside with them, thereby affecting the paternity confidence of the young women’s husbands and hence their incentives, is crucial. Our model fits the data on the relationship between inheritance, residence patterns and paternity confidence, and on the importance of paternity uncertainty.

Government response to consultation on choice and flexibility: Additional Paternity Leave and Pay

Sets out the Government's response to a public consultation on the legal and technical espects of the Additional Paternity Leave and Pay (APL&P) scheme