PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 12317028

Birth order effects and time allocation.

N Birdsall
View original source ↗Export metadata ↓

Abstract

"In this paper, a model is developed in which the explanation for birth-order effects does not rely on absence of capital markets, but follows from optimal allocation of parental time and goods among children over the childrearing years. The model yields two key results, which are then tested using 1967-1968 household survey data from urban Colombia.... It is shown that first and last-born children of mothers who do not work have an advantage over middle-borns.... At the same time, as predicted, there are no differences by birth order among children of working mothers. The persistence of birth-order effects even in high-income families indicates that such effects are at least in part due to the time constraint modelled; this is a strong result given the possibility of better substitutes for mother's time than allowed for in the model, and the likelihood that high-income families are able to purchase better substitutes."

Explore related subjects

AmericasBehaviorBiologyBirth OrderChild CareChild DevelopmentChild RearingColombiaDemographyDeveloping CountriesEconomicsEmploymentFamily CharacteristicsFamily RelationsLatin AmericaMothersParentsPopulationPopulation DynamicsSocial ClassSocioeconomic FactorsSouth AmericaTime FactorsDemographic FactorsEconomic FactorsEmployment--womenFamily And HouseholdFamily RelationshipsHigh Income PopulationMacroeconomic FactorsSocioeconomic StatusJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

N Birdsall. 1991. Birth order effects and time allocation.. https://pubmed.ncbi.nlm.nih.gov/12317028/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2018

Replication of Zika Virus in Human Prostate Cells: A Potential Source of Sexually Transmitted Virus.

BACKGROUND: While Zika virus (ZIKV) is mainly transmitted by mosquitoes, numerous cases of sexual transmission have been reported during recent outbreaks. Little is known about which host cell types or entry factors aid in mediating this sexual transmission. METHODS: In this study, we investigated ZIKV cell tropism by infecting 2 types of human prostate cells with 3 contemporary ZIKV isolates from persons infected in the Americas. We used real-time quantitative polymerase chain reaction and immunofluorescence analyses to measure infection and flow cytometry to detect entry factor expression. RESULTS: Here we show that ZIKV infects, replicates, and produces infectious virus in prostate stromal mesenchymal stem cells, epithelial cells, and organoids made with a combination of these cells. We also show that prostate cells express several well-characterized flavivirus attachment factors. In contrast, dengue virus does not infect or does not replicate in these prostate cells, although it is known to use similar receptors. CONCLUSIONS: Our results indicate that ZIKV favors infection of stromal cells more so than epithelial cells in organoids, possibly indicating a preference for stem cells in general. Overall, these results suggest that ZIKV replication occurs in the human prostate and can account for ZIKV secretion in semen, thus leading to sexual transmission.

Americas↗
PubMed2006

Returning forests analyzed with the forest identity.

Amid widespread reports of deforestation, some nations have nevertheless experienced transitions from deforestation to reforestation. In a causal relationship, the Forest Identity relates the carbon sequestered in forests to the changing variables of national or regional forest area, growing stock density per area, biomass per growing stock volume, and carbon concentration in the biomass. It quantifies the sources of change of a nation's forests. The Identity also logically relates the quantitative impact on forest expanse of shifting timber harvest to regions and plantations where density grows faster. Among 50 nations with extensive forests reported in the Food and Agriculture Organization's comprehensive Global Forest Resources Assessment 2005, no nation where annual per capita gross domestic product exceeded 4,600 dollars had a negative rate of growing stock change. Using the Forest Identity and national data from the Assessment report, a single synoptic chart arrays the 50 nations with coordinates of the rates of change of basic variables, reveals both clusters of nations and outliers, and suggests trends in returning forests and their attributes. The Forest Identity also could serve as a tool for setting forest goals and illuminating how national policies accelerate or retard the forest transitions that are diffusing among nations.

Americas↗
PubMed2006

Unique treatment policy for well-differentiated thyroid cancer in Japan: results of a questionnaire distributed to members of the Japanese Society of Thyroid Surgery and the International Association of Endocrine Surgeons.

Although surgery has been the mainstay of treatment for patients with well-differentiated thyroid cancer, the extents of thyroid resection and lymph node dissection adopted in Japan differ from those in other countries. Furthermore, regarding the indications for postoperative radiation therapy and hormonal therapy, and treatment modalities for cancer recurrence, there are marked discrepancies between Japan and other countries. A questionnaire survey was thus conducted among domestic and overseas thyroid surgeons to ascertain the actual treatment policy for well-differentiated thyroid cancer in Japan and various foreign countries. For small papillary carcinomas of 2.0 cm or less (T1), thyroid resection was more extensive in foreign countries than in Japan, although the extent of lymph node dissection was limited in the former. For large papillary carcinomas exceeding 3.0 cm (T2), on the other hand, total thyroidectomy was the treatment of first choice for all overseas respondents, but of only 20% in Japan, despite lymph node dissection being more extensive in Japan than in other countries. Overseas surgeons were much more likely to favor postoperative TSH suppression therapy and high-dose (131)I therapy. For recurrence following surgery for papillary thyroid cancer, both domestic and overseas respondents indicated surgical resection to be the most common treatment option, and favored high-dose (131)I therapy as well. In Japan, however, high-dose (131)I therapy is available only in a few institutions. Such limited indications for high-dose (131)I therapy in Japan may reflect a discrepancy in the frequency of total thyroidectomy, a prerequisite for postoperative high-dose (131)I therapy, between Japan and other countries. This is the first questionnaire study conducted in both Japan and other countries in relation to treatment modalities for thyroid cancer. The results reveal that there is a clear disparity in treatment policies between Japan and foreign countries.

Americas↗