Institutions and the transition to adulthood: Implications for fertility tempo in low-fertility settings

The number of countries experiencing very low fertility has been rising in recent years, garnering increasing academic, political and media attention. There is now widespread academic agreement that the postponement of fertility is a major contributing factor in the very low levels of fertility that have occurred, and yet most policy discussions have been devoted to increasing the numbers of children women have. We discuss factors in three institutions--the educational system, the labour market and the housing market--that may inadvertently have led to childbearing postponement. We highlight important components of the timing of childbearing, including its changing place within the transition to adulthood across countries and the significance of the demands of childbearing versus childrearing. Using illustrations from Europe, North America, Japan, Australia and New Zealand, we argue that the following all lead to younger childbearing: 1) an open education system whereby it is relatively easy to return to school after having dropped out for a while; 2) a shorter, smoother, easier school-to-work transition; 3) easier re-entry into the labour market after having taken time out for childrearing or any other reason; 4) greater capability of integrating childrearing into a career; 5) easier ability to obtain a mortgage with a moderately small down payment, moderately low interest rate and a long time period over which to repay the loan; and 6) easier ability to rent a dwelling unit at an affordable price. Conversely, reversing any or all of these factors would lead, other things being equal, to postponement of childbearing.

Left Regular Bands of Groups and the Mantaci--Reutenauer algebra

We develop the idempotent theory for algebras over a class of semigroups called left regular bands of groups (LRBGs), which simultaneously generalize group algebras of finite groups and left regular band (LRB) algebras. Our techniques weave together the representation theory of finite groups and LRBs, opening the door for a systematic study of LRBGs in an analogous way to LRBs. We apply our results to construct complete systems of primitive orthogonal idempotents in the Mantaci--Reutenauer algebra ${\sf{MR}}_n[G]$ associated to any finite group $G$. When $G$ is abelian, we give closed form expressions for these idempotents, and when $G$ is the cyclic group of order two, we prove that these recover idempotents introduced by Vazirani

Invariant Theory for the free left-regular band and a q-analogue

We examine from an invariant theory viewpoint the monoid algebras for two monoids having large symmetry groups. The first monoid is the free left-regular band on $n$ letters, defined on the set of all injective words, that is, the words with at most one occurrence of each letter. This monoid carries the action of the symmetric group. The second monoid is one of its $q$-analogues, considered by K. Brown, carrying an action of the finite general linear group. In both cases, we show that the invariant subalgebras are semisimple commutative algebras, and characterize them using Stirling and $q$-Stirling numbers. We then use results from the theory of random walks and random-to-top shuffling to decompose the entire monoid algebra into irreducibles, simultaneously as a module over the invariant ring and as a group representation. Our irreducible decompositions are described in terms of derangement symmetric functions introduced by D\'esarm\'enien and Wachs.Comment: final version, to appear in the Pacific Journal of Mathematic

Schools, Schooling, and Children's Support of Their Aging Parents

Intergenerational transfers play an important role in individuals' lives across the life course. In this paper I pull together theories on intergenerational transfers and social change to inform our understanding of how changes in the educational context influence children's support of their parents. By examining multiple aspects of a couple's educational context, including husbands' and wives' education and exposure to schools, this paper provides new information on the mechanisms through which changes in social context influence children's support of their parents. Using data from a rural Nepalese area I use multilevel logistic regression to estimate the relationship between schooling, exposure to schools, and the likelihood of couples giving to their parents. I find that both schooling and exposure to schools itself have separate, opposite effects on support of aging parents. Higher levels of schooling for husbands was associated with a higher likelihood of having given support to husbands' parents. On the other hand, increased exposure to schools for husbands and wives was associated with a lower likelihood of having given to wives' parents. Findings constitute evidence that multiple motivations for intergenerational support exist simultaneously and are related to social context through different mechanisms

Health Services, Schools, Attitudes, and Contraceptive Use: Tests of a Theoretical Model Among Rural Nepalese.

This dissertation uses new, highly detailed measures of dimensions of social context to advance our understanding of both attitudinal and programmatic mechanisms through which social context influences individual behavior. To illustrate, I focus on the relationship between dimensions of social context, specifically health services and schools, and contraceptive use in Nepal. Using data from the Chitwan Valley Family Study I employ multiple estimation techniques including multilevel-logistic and OLS regressions and discrete-time hazard modeling. To investigate the potential role of attitudinal mechanisms I explore how the health service and school contexts influence individuals’ attitudes about contraceptive methods, family size and composition, children, family, and non-family behaviors and how both context and these attitudes independently influence individuals’ contraceptive use. I find that women with positive attitudes about contraceptive methods and less family-oriented attitudes had higher rates of contraceptive use. Furthermore, women’s attitudes about children and family had strong effects independent from those of attitudes about contraception, indicating that these less closely connected attitudes play an integral part in women’s contraceptive use. When investigating the role of programmatic mechanisms I examine the separate effects of the provision of family planning, child, and maternal health services and, for schools, the effects of curriculum, teacher gender and training, students’ gender, and education costs. Because health service providers and schools are associated with a specific place, as new ones are built or existing ones change the services they offer, the distribution of these dimensions across physical space changes. Furthermore, because information about health services and schools is transmitted throughout communities through social channels, their potential realm of influence is also geographically disperse. Consequently, I use an expanded conceptualization of the influence of social context and estimate models with geographically weighted measures of health services and schools that incorporate all the providers and schools in the study area. My analyses using these geographically weighted measures indicate that these dimensions of health services and schools all influence contraceptive behavior. I also find evidence that women’s attitudes about children, the importance of childbearing, and roles within the family are mechanisms through which health services and schools influence contraceptive use.Ph.D.SociologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/57611/2/sbrauner_1.pd

Precocious and Early Central Puberty in Children With Pre-existing Medical Conditions: A Single Center Study

Background: Precocious and early puberty are reported findings in children with pre-existing medical conditions including certain syndromes. Series pertaining to such situations are limited.Methods: A retrospective, single-center study was conducted on children with central precocious puberty (onset before the age of 8 years in girls and 9 years in boys) or early puberty (onset between 8 and 9 years in girls and between 9 and 10.5 years in boys) diagnosed on the background of a known pre-existing chronic significant medical condition. Patients with a CNS tumor and those exposed to cranial irradiation were excluded.Results: Precocious puberty was diagnosed in 13 patients and early puberty in 12. Mean age at onset of puberty was 6.65 ± 2.3 years in girls (n = 15) and 9.4 ± 0.84 years in boys (n = 10). The most common disorders were psychomotor delay (n = 12), psychiatric disorders (n = 7) and/or epilepsy (n = 5). Precocious or early puberty was among the symptoms experienced by patients with a variety of syndromes including lipofuscinosis (2 siblings), Dravet syndrome and Silver-Russel syndrome. Pituitary stalk interruption with agenesis of olfactory bulbs and optic nerve atrophy was found on imaging in one patient who presented with blindness, epilepsy, and autism spectrum disorder. The other diseases associated with precocious or early puberty are adrenocorticotropic deficiency, dyspraxia and bone abnormalities, glomerulopathy with complete renal failure, and repeated intra-fetal deaths in the mother. Karyotype analysis revealed chromosomal duplication (chromosome 15 in 2 cases; chromosomes 17 and 11 in one case each) in 4 of 8 patients evaluated.Conclusions: Data from patients with complex disease who experience precocious or early puberty may provide clues regarding the genetic determinants of pubertal development