首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   18962篇
  免费   200篇
  国内免费   1篇
管理学   2812篇
民族学   134篇
人口学   3188篇
丛书文集   35篇
理论方法论   1113篇
综合类   440篇
社会学   8078篇
统计学   3363篇
  2023年   54篇
  2020年   144篇
  2019年   186篇
  2018年   1863篇
  2017年   1920篇
  2016年   1297篇
  2015年   201篇
  2014年   263篇
  2013年   1494篇
  2012年   618篇
  2011年   1364篇
  2010年   1211篇
  2009年   957篇
  2008年   979篇
  2007年   1175篇
  2006年   206篇
  2005年   421篇
  2004年   422篇
  2003年   368篇
  2002年   263篇
  2001年   230篇
  2000年   218篇
  1999年   184篇
  1998年   133篇
  1997年   131篇
  1996年   159篇
  1995年   110篇
  1994年   110篇
  1993年   98篇
  1992年   144篇
  1991年   124篇
  1990年   118篇
  1989年   114篇
  1988年   105篇
  1987年   91篇
  1986年   97篇
  1985年   111篇
  1984年   115篇
  1983年   127篇
  1982年   99篇
  1981年   89篇
  1980年   86篇
  1979年   95篇
  1978年   92篇
  1977年   81篇
  1976年   70篇
  1975年   70篇
  1974年   59篇
  1973年   63篇
  1971年   53篇
排序方式: 共有10000条查询结果,搜索用时 906 毫秒
821.
Although subprime mortgage lending and unemployment were largely responsible for the wave of foreclosures during the Great Recession, additional sources of financial risk may have exacerbated the crisis. We hypothesize that many parents sending children to college were financially overextended and vulnerable to foreclosure as the economy contracted. With commuting zone panel data from 2006 to 2011, we show that increasing rates of college attendance across the income distribution in one year predict a foreclosure rate increase in subsequent years, net of fixed characteristics and changes in employment, refinance debt, house prices, and 19-year-old population size. We find similar evidence of college-related foreclosure risk using longitudinal household data from the Panel Study of Income Dynamics. Our findings uncover a previously overlooked dimension of the foreclosure crisis, and highlight mortgage insecurity as an inadvertent consequence of parental investment in higher education.  相似文献   
822.
This study illuminates the association between cigarette smoking and adult mortality in the contemporary United States. Recent studies have estimated smoking-attributable mortality using indirect approaches or with sample data that are not nationally representative and that lack key confounders. We use the 1990–2011 National Health Interview Survey Linked Mortality Files to estimate relative risks of all-cause and cause-specific mortality for current and former smokers compared with never smokers. We examine causes of death established as attributable to smoking as well as additional causes that appear to be linked to smoking but have not yet been declared by the U.S. Surgeon General to be caused by smoking. Mortality risk is substantially elevated among smokers for established causes and moderately elevated for additional causes. We also decompose the mortality disadvantage among smokers by cause of death and estimate the number of smoking-attributable deaths for the U.S. adult population ages 35+, net of sociodemographic and behavioral confounders. The elevated risks translate to 481,887 excess deaths per year among current and former smokers compared with never smokers, 14 % to 15 % of which are due to the additional causes. The additional causes of death contribute to the health burden of smoking and should be considered in future studies of smoking-attributable mortality. This study demonstrates that smoking-attributable mortality must remain a top population health priority in the United States and makes several contributions to further underscore the human costs of this tragedy that has ravaged American society for more than a century.  相似文献   
823.
This study introduces a new sample that links people and families across 1860, 1880, and 1900 census data to explore the intergenerational impact of slavery on black families in the United States. Slaveholding—the number of slaves owned by a single farmer or planter—is used as a proxy for experiences during slavery. Slave family structures varied systematically with slaveholding sizes. Enslaved children on smaller holdings were more likely to be members of single-parent or divided families. On larger holdings, however, children tended to reside in nuclear families. In 1880, a child whose mother had been on a farm with five slaves was 49 % more likely to live in a single-parent household than a child whose mother had been on a farm with 15 slaves. By 1900, slaveholding no longer had an impact. However, children whose parents lived in single-parent households were themselves more likely to live in single-parent households and to have been born outside marriage.  相似文献   
824.
This article presents an assessment of individual uncertainty about longevity. A survey performed on 3,331 French people enables us to record several survival probabilities per individual. On this basis, we compute subjective life expectancies (SLE) and subjective uncertainty regarding longevity (SUL), the standard deviation of each individual’s subjective distribution of her or his own longevity. It is large and equal to more than 10 years for men and women. Its magnitude is comparable to the variability of longevity observed in life tables for individuals under 60, but it is smaller for those older than 60, which suggests use of private information by older respondents. Our econometric analysis confirms that individuals use private information—mainly their parents’ survival and longevity—to adjust their level of uncertainty. Finally, we find that SUL has a sizable impact, in addition to SLE, on risky behaviors: more uncertainty on longevity significantly decreases the probability of unhealthy lifestyles. Given that individual uncertainty about longevity affects prevention behavior, retirement decisions, and demand for long-term care insurance, these results have important implications for public policy concerning health care and retirement.  相似文献   
825.
Rebecca Glauber 《Demography》2018,55(5):1663-1680
Many studies have shown that women pay a wage penalty for motherhood, whereas men earn a wage premium for fatherhood. A few recent studies have used quantile regression to explore differences in the penalties across the wage distribution. The current study builds on this research and explores trends in the parenthood penalties and premiums from 1980 to 2014 for those at the bottom, middle, and top of the wage distribution. Analyses of data from the Current Population Survey show that the motherhood wage penalty decreased, whereas the fatherhood wage premium increased. Unconditional quantile regression models reveal that low-, middle-, and high-earning women paid similar motherhood wage penalties in the 1980s. The motherhood wage penalty began to decrease in the 1990s, but more so for high-earning women than for low-earning women. By the early 2010s, the motherhood wage penalty for high-earning women was eliminated, whereas low-earning women continued to pay a penalty. The fatherhood wage premium began to increase in the late 1990s, although again, more so for high-earning men than for low-earning men. By the early 2010s, high-earning men received a much larger fatherhood wage premium than low- or middle-earning men.  相似文献   
826.
In Africa and elsewhere, educated women tend to marry later than their less-educated peers. Beyond being an attribute of individual women, education is also an aggregate phenomenon: the social meaning of a woman’s educational attainment depends on the educational attainments of her age-mates. Using data from 30 countries and 246 birth cohorts across sub-Saharan Africa, we investigate the impact of educational context (the percentage of women in a country cohort who ever attended school) on the relationship between a woman’s educational attainment and her marital timing. In contexts where access to education is prevalent, the marital timing of uneducated and highly educated women is more similar than in contexts where attending school is limited to a privileged minority. This across-country convergence is driven by uneducated women marrying later in high-education contexts, especially through lower rates of very early marriages. However, within countries over time, the marital ages of women from different educational groups tend to diverge as educational access expands. This within-country divergence is most often driven by later marriage among highly educated women, although divergence in some countries is driven by earlier marriage among women who never attended school.  相似文献   
827.
Starting in 2006, respondents in the biennial U.S. Health and Retirement Study were asked to submit biomarkers every other wave and were notified of several results. Rates of undiagnosed high blood pressure and diabetes according to these biomarkers were 1.5 % and 0.7 %, respectively. An intent-to-treat analysis suggests that collection and notification had small effects on the average respondent and may have reduced health care utilization. Among respondents who received notification of potentially dangerous biomarker levels, subsequent rates of new diagnosis and associated pharmaceutical usage increased by 20 to 40 percentage points, an order of magnitude above baseline. High blood glucose A1C was associated with a 2.2 % drop in weight and an increase in exercise among respondents without a previous diagnosis of diabetes. Notifications appear also to have altered health behaviors by spouses, suggesting household responses to health maintenance. Biomarker collection seems to have altered circumstances for an interesting minority of HRS respondents.  相似文献   
828.
We assess the effects of the population age structure and the population dynamics on economic growth. Following recent research, we focus on the generational turnover effect to characterize the influence of birth and death rates, depending on the age profile of individual consumption, the extent of annuity market imperfections, and the willingness of households to shift consumption over time. Using data from the National Transfer Accounts on age profiles of consumption for a number of different countries, we assess—in a comparative way—the sign and the magnitude of the generational turnover effect and its impact on economic growth. We find considerable cross-country differences and trace them back to the underlying variation in demography and in the age structure of consumption.  相似文献   
829.
This paper investigates the impact of pension income on living arrangements of the elderly. Taking advantage of a unique opportunity due to the recent establishment and expansion of the New Rural Pension Scheme in China, we explicitly address the endogeneity of pension status and pension income through a fixed-effect model with instrumental variable approach by exploiting exogenous time variation in the program implementation at county level. We find an overall positive effect of pension income on independent living as well as considerable heterogeneity. The positive income effects of the NRPS are concentrated among the elderly with adult children living nearby, of higher socio-economic status, and with better health at baseline; for other groups, the effects are insignificant. We also find that more generous programs exhibit larger effects. Our results highlight that living arrangement is multidimensional in rural China.  相似文献   
830.
We find a strong positive raw correlation between black exposure to whites in their school district and the prevalence of later mixed-race (black-white) births, consistent with the literature on residential segregation and endogamy. However, that relationship is significantly attenuated by the addition of a few control variables, suggesting that individuals with higher propensities to have mixed-race births are more likely to live in desegregated school districts. We exploit quasi-random variation from court-ordered school desegregation to estimate causal effects of school desegregation on mixed-race childbearing, finding small to moderate effects that are largely statistically insignificant. Because the upward trend across cohorts in mixed-race childbearing was substantial, separating the effects of desegregation plans from secular cohort trends is difficult; results are sensitive to how we specify the cohort trends and to the inclusion of Chicago/Cook County in the sample. The fact that the addition of a few control variables substantially weakens the cross-sectional relationship between lower levels of school segregation and higher rates of mixed-race childbearing suggests that a substantial portion of the observed correlation is likely due to who chooses to live in places with desegregated schools. Researchers should be cautious about interpreting raw correlations between segregation—whether residential or school—and other outcomes as causal. Our results also point to the need to carefully explore specification of cohort effects in quasi-experimental designs for treatments where cumulative exposure is important.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号