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   1950篇
  免费   35篇
各国政治   42篇
工人农民   16篇
世界政治   297篇
外交国际关系   91篇
法律   1301篇
中国共产党   24篇
中国政治   66篇
政治理论   117篇
综合类   31篇
  2019年   3篇
  2018年   3篇
  2015年   2篇
  2014年   5篇
  2013年   4篇
  2012年   125篇
  2011年   140篇
  2010年   42篇
  2009年   27篇
  2008年   115篇
  2007年   144篇
  2006年   185篇
  2005年   168篇
  2004年   163篇
  2003年   135篇
  2002年   120篇
  2001年   99篇
  2000年   101篇
  1999年   51篇
  1998年   22篇
  1997年   10篇
  1996年   14篇
  1995年   20篇
  1994年   31篇
  1993年   19篇
  1992年   15篇
  1991年   13篇
  1990年   8篇
  1989年   10篇
  1988年   16篇
  1987年   13篇
  1986年   12篇
  1985年   9篇
  1984年   9篇
  1983年   19篇
  1982年   10篇
  1981年   14篇
  1980年   19篇
  1979年   13篇
  1978年   5篇
  1977年   6篇
  1975年   2篇
  1974年   4篇
  1964年   3篇
  1963年   5篇
  1962年   8篇
  1961年   5篇
  1960年   3篇
  1959年   4篇
  1956年   2篇
排序方式: 共有1985条查询结果,搜索用时 15 毫秒
91.
近几年来美国把对泰国援助中一部分“贈欵”改为貸欵,泰报认为是援助減少了。作者认为貸欵也是援助,但可能使泰国经济发展計划降低要求或中止,言外之音是希望增加“贈欵”。  相似文献   
92.
不久以前,苏聯的研究工作者已經開始編篡一系列东南亚國家的近代史;其中對这些國家的民族解放運动史研究較少。本文則試图探討一下十九世纪70—90年代在馬來亚反對英国殖民主义者的起义。①內容广泛的英國歷史編篡学在關于英國佔领馬  相似文献   
93.
In order to assess the effect of Social Security reform on current and future workers, it is essential to accurately characterize the initial situations of representative workers affected by reform. For the purpose of analyzing typical reforms, the most important characteristic of a worker is the level and pattern of his or her preretirement earnings. Under the current system, pensions are determined largely by the level of the workers' earnings averaged over their work life. However, several reform proposals would create individual retirement accounts for which the pension would depend on the investment accumulation within the account. Thus, the pension would also depend on the timing of the contributions into the account and hence on the exact shape of the worker's lifetime earnings profile. Most analysis of the distributional impact of reform has focused, however, on calculating benefit changes among a handful of hypothetical workers whose relative earnings are constant over their work life. The earnings levels are not necessarily chosen to represent the situations of workers who have typical or truly representative earnings patterns. Consequently, the results of such analysis can be misleading, especially if reform involves introducing a fundamentally new kind of pension formula. This article presents two broad approaches to creating representative earnings profiles for policy evaluation. First, we use standard econometric methods to predict future earnings for a representative sample of workers drawn from the Survey of Income and Program Participation (SIPP). Our statistical estimates are based on a simple representation of typical career earnings paths and a fixed-effect statistical specification. Because our estimation file contains information on each worker's annual earnings from 1951 through 1996 as reported in the Social Security Administration's earnings files, we have a record (though an incomplete one) of the actual earnings that will be used to determine future benefit payments. Our estimates of the earnings function permit us to make highly differentiated predictions of future earnings for each member of our sample. By combining the historical information on individual earnings with our prediction of future earnings up through the normal retirement age, our first approach produces tens of thousands of predicted career earnings paths that can be used in microsimulation policy analysis. Our second approach to creating lifetime earnings profiles is similar in some ways to the traditional method. For example, it is based on the creation of only a handful of "stylized" career earnings patterns. An important difference with the traditional method, however, is that we define the career earnings patterns so that they are truly representative of patterns observed in the workforce. We use simple mathematical formulas to characterize each stylized earnings pattern, and we then produce estimates of the average path of annual earnings for workers whose career earning path falls within each of the stylized patterns we have defined. Finally, we calculate the percentage of workers in successive birth-year cohorts who have earnings profiles that match each of the stylized earnings patterns. Although this method may seem simple, it allows the analyst to create stylized earnings patterns that are widely varied but still representative of earnings patterns observed among sizable groups of U.S. workers. The effects of policy reforms can then be calculated for workers with each of the stylized earnings patterns. Our analysis of U.S. lifetime earnings patterns and of the impact of selected policy reforms produces a number of findings about past trends in earnings, typical earnings patterns in the population, and the potential impact of reform. The analysis focuses on men and women born between 1931 and 1960. Along with earlier analysts, we find that men earn substantially higher lifetime wages than women and typically attain their peak career earnings at a somewhat earlier age. However, the difference in career earnings patterns between men and women has narrowed dramatically over time. Workers with greater educational attainment earn substantially higher wages than those with less education, and they attain their peak career earnings later in life. For example, among men with the least education, peak earnings are often attained around or even before age 40, whereas many men with substantial postsecondary schooling do not reach their peak career earnings until after 50. Our tabulations of the lifetime earnings profiles of the oldest cohorts (born around 1930) and projections of the earnings of the youngest profiles (born around 1960) imply that the inequality of lifetime earnings has increased noticeably over time. Women in the top one-fifth of female earners and men in the top one-fifth of male earners are predicted to receive a growing multiple of the economy-wide average wage during their career. Women born between 1931 and 1935 who were in the top fifth of female earners had lifetime average earnings that were approximately equal to the average economy-wide wage. In contrast, women born after 1951 who were in the top fifth of earners are predicted to earn almost 50 percent more, that is, roughly 150 percent of the economy-wide average wage. Women with a lower rank in the female earnings distribution will also see gains in their lifetime average earnings, but their gains are predicted to be proportionately much smaller than those of women with a high rank in the distribution. Men with high earnings are also predicted to enjoy substantial gains in their relative lifetime earnings, while men with a lower rank in the earnings distribution will probably see a significant erosion in their typical wages relative to the economy-wide average wage. That is mainly the result of a sharp decline in the relative earnings of low-wage men born after 1950. In creating stylized earnings profiles that are representative of those of significant minorities of U.S. workers, we emphasized three critical elements of the earnings path: the average level of earnings over a worker's career, the upward or downward trend in earnings from the worker's 30s through his or her early 60s, and the "sagging" or "hump-shaped" profile of earnings over the worker's career. That classification scheme yields 27 characteristic patterns of lifetime earnings. Surprisingly, the differnce between men and women within each of those categories is quite modest. The main difference between men and women is in the proportions of workers who fall in each category. Only 14 percent of men born between 1931 and 1940 fall in earnings categories with the lowest one-third of lifetime earnings, whereas 53 percent of women born in those years have low-average-earnings profiles. On the other hand, women born in those years are more likely to have a rising trend in lifetime earnings, while men are more likely to have a declining trend. We find that the distribution of lifetime earnings contains relatively more workers with below-average earnings and relatively fewer with very high earnings than assumed in the Social Security Administration's traditional policy analysis. For example, the "low earner" traditionally assumed by the Office of the Chief Actuary is assigned a level of average lifetime earnings that we find to be higher than the average earnings of persons in the bottom one-third of the lifetime earnings distribution. The stylized earnings profiles developed here can be used for policy evaluation, and the results can be compared with those from the more traditional analysis. That comparison produces several notable findings. Because earnings profiles that are actually representative of the population tend to have lower average earnings than assumed in the traditional analysis, workers typically accumulate somewhat less Social Security wealth than implied in the traditional analysis. On the other hand, because the basic benefit formula is tilted in favor of lower-income workers, the internal rate of return on Social Security contributions is somewhat higher than detected in the traditional analysis. Moreover, the primary insurance amount measured as a percentage of the worker's average indexed earnings tends to be higher than implied by the traditional analysis. Finally, the stylized earnings patterns can be used to compare benefit levels enjoyed by workers under the traditional Social Security formula and under an alternative plan based on individual investment accounts. That comparison shows, as expected, that the traditional formula favors low-wage workers and one-earner couples, while an investment account favors single, high-wage workers. Comparing two workers with the same lifetime average earnings, the traditional formula favors workers with rising earnings profiles (that is, with lifetime earnings heavily concentrated at the end of their career), while investment account pensions favor workers with declining earnings profiles (that is, with earnings concentrated early in their career).  相似文献   
94.
Panel surveys interview the same individuals more than once over a period of time. Attrition from the survey occurs when those individuals die, refuse to be interviewed again, or, for some other reason, cannot be contacted. If the original sample was representative of a specific population, then survey analysis may provide misleading conclusions about changes in population characteristics over time if these individuals leave the sample in a nonrandom way. Therefore, it is important to identify the characteristics of individuals who leave the survey for various reasons. This article explores the extent of and reasons for attrition in the New Beneficiary Survey (NBS) between the first interview in 1982 and the followup interview in 1991. Presented is a comparison of the characteristics of survivors (the reinterviewed sample) with attriters (those in the sample not reinterviewed) from the retired-worker and disabled-worker samples. The article explores a variety of potential determinants of attrition to the probability of attrition. These determinants are examined alone and in a multivariate framework. The NBS sample population is drawn from and linked to Social Security Administrative records, which have exact matched data on mortality as a cause of attrition. These data do not depend on survey-reported reasons for attrition; hence, it allows the examination of the differences in the patterns and predictors of attrition due to death and due to other reasons, primarily, the refusal to be interviewed. Attrition due to death must be identified precisely because misidentification of death as refusal to be interviewed may lead researchers to infer more selective attrition than might be the case. Different patterns of attrition are evident in the comparison of attrition levels and the determinants of attrition for the retired and disabled samples, both composed of persons with relatively high mortality risk. In particular, individuals' health, health insurance coverage, and level of education have different impacts on their likelihood of attrition. In general, it appears that refusal to be interviewed is more evenly spread across populations and characteristics than is death. The analysis shows that attrition due to death and attrition due to refusal are quite different processes, even though health conditions play a role in both processes. The results suggest that because attrition patterns (including death) may be quite different across population samples, sample-specific attrition patterns must be analyzed over the lifetime of any panel study. Long-term studies of panel attrition are necessary to provide researchers analyzing the data with information on potential biases due to nonrandom attrition.  相似文献   
95.
香港,是世界公认的经济繁荣之地,尤其是其金融、贸易中心的地位,无它地可取代。俯览今日的香港经济,不能不注意到这样一个现实:那里,除了外资、港资,还有一个重要的中资群体。中资群体的存在和发展,可以令内地人振奋,也会给内地人以启迪。中资企业举足轻重据统计,截止目前,香港中资企业令人咋舌:1800家,总资产约425亿美元,  相似文献   
96.
Hjelmeland H  Grøholt B 《危机》2005,26(2):64-72
Research has shown that the prevalence of deliberate self-harm (DSH) is higher in adolescents than in adults, but little is known about other differences. In this study we compare adolescent and adult DSH-patients regarding factors contributing to the suicidal act. In two regions in Norway, 98 persons under 20 years of age and 83 older persons were interviewed following an act of DSH. They were compared regarding intentions involved in the DSH, precipitating circumstances, level of suicidal intent, medical seriousness of the act, depression, hopelessness, and self-esteem. Few differences were found. The adults more often wanted to escape from unbearable thoughts or situations, or to receive care and attention. Adults also reported a slightly higher level of medical seriousness of the DSH act, more psychiatric problems, and substance abuse. The similarities between young and adult DSH-patients are striking. The differences found are most likely related to factors of age itself, such as cognitive immaturity, impulsivity, and lack of experience in enduring problems.  相似文献   
97.
98.
99.
100.
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