Migration and fertility: competing hypotheses re-examined

Competing views exist concerning the impact of geographical mobility on childbearing patterns. Early research shows that internal migrants largely exhibit fertility levels dominant in their childhood environment, while later studies find migrants’ fertility to resemble more closely that of natives at destination. Some authors attribute the latter to adaptation, but others claim that selection of migrants by fertility preferences may be the cause. Moreover, the short-term fertility-lowering-effect of residential relocation has also been proposed and challenged in the literature. This paper contributes to the existing discussion by providing an analysis of the effect of internal migration on fertility of post-war Estonian female cohorts. We base our study on retrospective event-history data and apply intensity regression for both single and simultaneous equations. Our analysis shows that first, the risk of birth decreases with increasing settlement size and the decrease is larger for higher-order parities. Second, it shows that migrants, whatever their origin, exhibit fertility levels similar to those of non-migrants at destination. Our further analysis supports the adaptation hypothesis. We find no evidence on strong selectivity of migrants by fertility preferences, although we observe elevated fertility levels after residential relocations arsing from union formation.Estonia, event history analysis, fertility, internal migration

Family change and migration in the life course

This article is an introduction to Special Collection 6 of Demographic Research whose articles investigate the interrelations between the family and migration behaviour of individuals in industrialised countries. We first review the life-course approach and previous research on the interplay between family change and migration. We then describe the contribution of the articles in the collection. This is followed by a discussion of selected issues raised in the papers and an outline of future research avenues. We argue that the life-course approach and event-history analysis offer a fruitful framework to examine how individuals simultaneously structure their family lives and residential trajectories, and thus shape demographic change in society.event history analysis, family, fertility, life-course approach, migration, residential mobility

Premarital cohabitation and divorce: Support for the "Trial Marriage" Theory?

A number of studies show that premarital cohabitation is associated with an increased risk of subsequent marital dissolution. Some argue that this is a consequence of selection effects and that once these are controlled for premarital cohabitation has no effect on dissolution. We examine the effect of premarital cohabitation on subsequent marital dissolution by using rich retrospective life-history data from Austria. We model union formation and dissolution jointly to control for unobserved selectivity of cohabiters and non-cohabiters. Our results show that those who cohabit prior to marriage have a higher risk of marital dissolution. However, once observed and unobserved characteristics are controlled for, the risks of marital dissolution for those who cohabit prior to marriage are significantly lower than for those who marry directly. The finding that premarital cohabitation decreases the risk of marital separation provides support for the "trial marriage" theory.Austria, event history analysis, rural, selection effects, union dissolution, urban

Fertility differences by housing type: an effect of housing conditions or of selective moves?

This study examines fertility variation across housing types and childbearing patterns after housing changes. While the effect of family changes on housing choices has been studied in detail, little is known about childbearing patterns within various housing types, despite the fact that many studies suggest housing as an important determinant of fertility. We use longitudinal register data from Finland and apply hazard regression. Firstly, we observe a significant variation in the fertility levels across housing types – fertility is highest among couples in single-family houses and lowest among those in apartments, with the variation remaining significant even after controlling for the demographic and socio-economic characteristics of women. Secondly, our results show elevated fertility levels after couples have changed their housing, suggesting that much of the fertility variation across housing types could be attributed to selective moves. Thirdly, the study also reveals relatively a high risk of third birth for couples in single-family houses several years after the move, suggesting that living in spacious housing and in a family-friendly environment for a longer time may lead to higher fertility.Finland, event history analysis, fertility, housing, migration, residential mobility

High fertility in city suburbs: compositional or contextual effects?

Fertility rates are known to be higher in city suburbs. One interpretation is that the suburban ‘context’ influences the behaviour of individuals who reside there while an alternative is that the ‘composition’ of the suburban population explains the higher fertility levels. Furthermore, suburban in-migrants who intend to have children may have a significant influence on suburban fertility rates. Using Finnish longitudinal register data we show that fertility rates are higher in the suburbs and rural areas and lower in the cities. While fertility variation across these residential contexts decreases significantly after controlling for women’s demographic and socio-economic characteristics, it does not disappear entirely suggesting that the local context may have some influence on fertility. While movers to suburbs do display higher fertility levels than non-migrant residents, their overall impact is not great because they form a small share of the suburban population.Finland, event history analysis, fertility, migration, residential mobility, rural areas, suburban areas, urban areas

Migration and union dissolution in a changing socio-economic context

Previous studies show that family migration is usually to the benefit of the man’s professional career and that it has a negative impact on the woman’s economic well-being and employment. This study extends previous research by examining the effect of family migration on union dissolution. We use the event-history data of two retrospective surveys from Russia and apply hazard regression. The analysis shows that couples who move frequently over long distances have a significantly higher risk of union dissolution than couples who do not move or move only once. Our further analysis reveals that the risk of disruption for frequent movers is high when the migrant woman has a job. Frequent migrants had a high risk of union dissolution during the Soviet period but they faced no such risk during the post-Soviet socio-economic transition. We argue that frequent moving increases union instability through a variety of mechanisms, the effect of which may vary across socio-economic contexts.event history analysis, migration, rural areas, Russia, union dissolution, urban

High Suburban Fertility: Evidence from Four Northern European Countries

This study examines fertility variation across different residential contexts in four Northern European countries: Denmark, Finland, Norway and Sweden. We move beyond the conventional urban-rural focus of most previous studies of within-nation variations in fertility by distinguishing between urban centres and suburbs of cities and towns. We base our study on aggregate and individual-level register data and our analysis shows that fertility levels are significantly higher in suburbs than in urban centres; this pattern has persisted over the past quarter of a century for all four countries. A parity-specific analysis of Swedish register data reveals that total fertility varies between central cities and suburbs due to the relatively high first- and second-birth propensities in the suburbs. Further analysis shows that fertility variation between the central cities and suburbs persists after controlling for women’s socioeconomic characteristics. We discuss the role of various factors in accounting for high suburban fertility including omitted individual characteristics, contextual factors and selective residential moves of couples planning to have a child.fertility, Nordic countries, rural, suburban, urban

Satellite Constellations - 2021 Industry Survey and Trends

Large satellite constellations are becoming reality. Starlink has launched over 1600 spacecraft in 2 years since the launch of the first batch, Planet has launched over 450 in total, OneWeb over 200 and counting. Every month new constellation projects are announced, some for novel applications. First part of the paper focuses on the industry survey of 251 commercial satellite constellations. Statistical overview of applications, form factors, statuses, manufacturers, founding years is presented including early stage and cancelled projects. Large number of commercial entities have launched at least one demonstrator satellite, but operational constellations have been much slower to follow than follow. One reason could be that funding is raised in stages and the sustainability of most business models remains to be proven. Second half of the paper examines constellations by selected applications and discusses trends in applications, satellite masses, orbits and manufacturers over the past 5 years. Earliest applications challenged by NewSpace were AIS, Earth Observation, Internet of Things (IoT) and Broadband Internet. Recent years have seen diversification into majority of applications that have been planned or performed by government or military satellites and beyond

The Human Octopus: Controlling Supernumerary Hands with the Help of Virtual Reality

Selles teadustöös uuritakse “inimkaheksajala” fenomeni, mis kujutab endast rohkem kui ühe käepaari kasutamist virtuaalreaalsuse tehnoloogia abil. Selleks koostati neli eksperimenti, et jälgida, kuidas katseisikud tegutsevad erineva arvu käepaaridega, mille juhtimiseks on erinevad strateegiad. Uuritavad juhtimisstrateegiad olid viivituse lisamine, haardeulatuse ning positsiooni muutmine ja pealiigutuste kasutamine. Eksperimentide käigus leiti, et rohkemate käepaaride kasutamine ei taga alati ülesande täitmisel paremat tulemust. Kuid käte haardeulatuse muutmine võib oluliselt parandada efektiivsust, kui see on antud ülesande jaoks sobilikum. Lisaks sellele leiti, et viivituse lisamine ning positsiooni muutmine oluliselt vähendavad käte loomulikkust ning omanikutunnet. Pealiigutuste kaasamine käte juhtimisstrateegiale on aga kindlasti väärt edasist uurimist. Lisaks sellele on transformeeritud kehakujutusega avataridel suur potentsiaal meelelahutusäris.This thesis is about investigating the “human octopus” phenomenon which involves con-trolling various supernumerary hands with the help of virtual reality and hand tracking technology. A set of experiments were developed in order to observe how subjects operate with different number and control strategies of supernumerary hands. The control strate-gies involved inserting delay into the supernumerary hands and adjusting their movement scale or position. It was found that having more hands to operate with does not necessarily mean that one would be more successful performing a certain task. However, one could make supernumerary hands more effective by adjusting movement scale of the hands if it suits the task better. Furthermore, the natural feeling and ownership of the hands seems to diminish when delay is inserted into the hands or their position is altered. Therefore, body avatar extension is a difficult task and needs to be done carefully in order for it to feel natural. It was also found that using head movement to assist controlling supernumerary hands is something that is worth researching more into. Body avatars with supernumerary hands also have great potential in entertainment industry