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In this data visualization, the authors document trends in abstaining from sex while never married for U.S. women born 1938–1939 to 1982–1983. Using data from the six most recent National Surveys of Family Growth, the authors’ estimates suggest that for women born in the late 1930s and early 1940s, 48 percent to 58 percent reported abstaining from sex while never married. Abstinence then declined rapidly among women born in the late 1940s through the early 1960s, leveling off at between 9 percent and 12 percent for more recent birth cohorts. Thus, for U.S. women born between the mid-1960s and the early 1980s, roughly one in nine abstained from sex while never married.

Background: In a heavily cited paper, Finer (2007) asserted that by age 30, 82Š of US women born 1939-1948 engaged in premarital sex, increasing to 94Š for those born 1969-1978. Using the same data, our age 30 estimates are 55Š and 87Š for women born 1939-1948 and 1969-1978. Our analyses thus document strikingly different levels and trends. Methods: We replicate Finer's single-decrement Kaplan-Meier estimates of premarital sex using Cycles 3-6 of the National Survey of Family Growth, the same data as analyzed by him. We then contrast such single-decrement estimates for both premarital sex and first marriage with estimates of the simple percentages in three states: an origin state in which women begin life as never-married virgins and two destination states for first sex and for first marriage, depending on which occurs first. These analyses provide an empirical illustration of the fact that single-decrement estimates cannot be interpreted as simple percentages for demographic processes involving multiple decrements. Results: Our cohort estimates document increases in the percent of US women who had premarital sex by age 25, rising from 53Š to 75Š, 83Š, and 87Š for those born 1939-1948, 1949-1958, 1959-1968, and 1969-1978, respectively. Contribution: Our cohort analyses reveal sharp increases in premarital sex for US women born between 1939 and 1968, with increases most rapid for those born in the 1940s and 1950s. Our findings also reemphasize a standard lesson from formal demography - that single-decrement life table estimates cannot be interpreted as simple percentages for a multiple-decrement demographic process.

Persistently high poverty among families with children, a lack of equal opportunity, stalled intergenerational mobility, and inequality have all risen up the agenda for federal, state, and local policymakers. Children born into low-income families face barriers to success in each stage of life from birth till age 40. Using data on a representative group of American children and a life cycle model to track their progress from the earliest years through school and beyond, we show that well-evaluated, targeted interventions can close over 80% of the gap between more and less advantaged children in the proportion that ends up middle class by middle age. These interventions can also greatly improve social mobility and enhance the lifetime incomes of less advantaged children.

Motivated by long-standing debates between abstinence proponents and sceptics, we examine how socio-economic factors influence premarital first births via: (i) age at first sexual intercourse and (ii) the risk of a premarital first birth following the onset of sexual activity. Factors associated with an earlier age at first intercourse will imply more premarital first births owing to increased exposure to risk, but many of these same factors will also be associated with higher risks of a premarital first birth following onset. Our analyses confirm previous findings that women from disadvantaged backgrounds are younger at first intercourse and have higher premarital first-birth risks than women from more advantaged backgrounds. However, differences in onset timing have a strikingly smaller influence on premarital first-birth probabilities than do differences in post-onset risks. Our findings thus suggest that premarital first births result primarily from differences in post-onset risk behaviours as opposed to differences in onset timing.

SiO2 Medical Products, Inc. (SiO) has developed a proprietary technology that greatly enhances protein recoveries and reduces extractables from commercial microplates used for bioanalytical assays and storage of biologics. SiO technology is based on plasma treatment that chemically modifies the surface of polypropylene with predominantly hydrogen-bond-acceptor uncharged polar groups. The resultant surface resists nonspecific protein adsorption over a wide range of protein concentrations, thereby eliminating the need to passivate (and hence potentially contaminate) the microplates with blocking proteins. High shelf-life stability and cleanliness of the plasma-treated microplates have been demonstrated using five different proteins for two common microplate formats. The protein recovery performance of plasma-treated microplates is found to be higher compared with commercial low-protein-binding microplates.

This study examines time with children among women who remain childless in young to middle adulthood. The authors identify biologically childless women aged 25 to 44 years in the June 2004-2008 Current Population Survey, and use their subsequent time use diaries in the 2004-2009 American Time Use Survey to measure their time with children. The authors pay particular attention to time with children who are not one’s “own” (by adoption or marriage) and to differences across educational groups of childless women. It is found that childless women frequently spend time with children, and childless women with no 4-year college degree are almost twice as likely to spend time with children as childless women with a 4-year degree. The authors also show how educational differences in childless women’s time with children are mediated by work patterns, residential arrangements, and especially union status. The findings suggest large class differences in how women experience the boundary between childlessness and parenthood.

Early studies of the impact of information technology (IT) on society suggested that it had a negative impact on social life as well as on mass media use. This article reviews the results from several subsequent studies both in the United States and other countries that show little such societal change in terms of users’ daily behavior. It then proceeds to document further negative evidence from two more recent large national surveys with high response rates: the 2006 General Social Survey (GSS), with more than 2,500 respondents, and the 2003—2005 American Time-Use Survey (ATUS), with more than 40,000 respondents, aged 18 and older. The GSS survey collected time-estimate data on particular social and media (mainly free-time) activities, while the ATUS study collected diary data on all daily activities across a single day. In general, Internet use was not consistently correlated with significantly lower levels of socializing or other social activities (such as church attendance) nor with lower time with mass communications media in the GSS. For reading and some other behaviors, the Internet was associated with increased media use. Respondents who reported more time on the Internet did report fewer social visits with relatives, but more visits with friends, compared to those who spent no time on the Internet. The main difference between users and nonusers in the ATUS was with time at paid work, which was only partially explained by higher Internet use by teens and on days off from work. For reading and some other behaviors, the Internet was associated with increased use.

Analysis of early time-diary studies suggests that television has had more impact on daily time than any other household technology in the past century. In the United States, viewing time has steadily increased from roughly ten weekly hours in the 1960s to sixteen hours today, encompassing almost half of all “free time” reported in the diaries. A prominent recent TV casualty has been time spent reading the newspaper, providing further support for the functional equivalence argument. This article shows that, so far at least, viewing time seems little affected by the Internet and other recent new technologies. Studies of the public’s satisfaction with various activities suggest that viewers find TV to be more enjoyable in the doing rather than in general, even though it may not be particularly challenging or demanding of concentration. Viewing time is also shown to be significantly related to long-term personal unhappiness.

This paper outlines decomposition methods for assessing how exposure affects prevalence and cumulative relative risk. Let x denote a vector of exogenous covariates and suppose that a single dimension of time t governs two event processes T1 and T2. If the occurrence of the event T1 determines entry into the risk of the event T2, then subgroup variation in T1 will affect the prevalence T2, even if subgroups in the population are otherwise identical. Although researchers often acknowledge this phenomenon, the literature has not provided procedures to assess the magnitude of an exposure effect of T1 on the prevalence of T2. We derive decompositions that assess how variation in exposure generated by direct and indirect effects of the covariates x affect measures of absolute and relative prevalence of T2. We employ a parametric but highly flexible specification for baseline hazard for the T1 and T2 processes and use the resulting parametric proportional hazard model to illustrate the direct and indirect effects of family structure when T1 is age at first sexual intercourse and T2 is age at a premarital first birth for data on a cohort of non-hispanic white U.S. women.

As more survey and opinion polling agencies collect their data using the Internet, questions arise about how representative Internet users are of the American population as a whole. We use a targeted module of IT-relevant questions added to the 2000, 2002, 2004 and 2006 samples in the General Social Survey (GSS) to analyze differences between Internet users and non-users. We devote particular attention to the issue of whether Internet use is associated with more or less diverse or ‘liberal’ political opinions and to how these associations have changed since 2000. In general, we found that where differences existed, they were in the direction of Internet users being more supportive of diverse and tolerant points of view than were non-users, consistent with the premise that going online is a way of expressing openness to opposing points of view and new experiences. However, the differences were often non-monotonic – that is, openness did not always increase progressively with the amount of Internet use. Mor...

We examine the relationship between marriage and welfare recidivism for women leaving a first welfare spell, using the 1979-2000 panels of the National Longitudinal Survey of Youth (NLSY). Previous studies have found that women who marry around the time of welfare exit have lower rates of welfare return than women who stay single. However, more marriages occur before or after welfare exit than occur at the time of welfare exit. We find that marriages that precede or follow welfare exit by more than 12 months are not associated with significantly lower rates of welfare return. We also confirm previous findings that marriages formed within a year of welfare exit are associated with reduced rates of welfare return. However, these reduced rates mostly indicate later welfare returns rather than fewer welfare returns. Overall, our findings indicate a much weaker association between marriage and welfare independence than has been previously reported for this time period.

This article borrows heavily from and summarizes a longer version produced last year by Fisher et al. (2007), and we are grateful as well for further discussions with Kimberly Fisher and Jonathan Gershuny to prepare this article. It first describes the 2006 American Heritage Time Use Study (AHTUS), developed by the Centre for Time Use Research (CTUR) at the Institute for Social and Economic Research at the University of Essex, and now housed at Oxford University. The AHTUS merges the new American Time Use Survey (ATUS), collected on a continuous basis beginning in 2003 by the US Bureau of Labor Statistics (BLS), with four previous national time-use studies collected at the University of Maryland and the University of Michigan. The resulting harmonized format makes it appropriate for a wide range of economic and sociological analyses. It is used here to identify several types of social change in the US across the latter half of the twentieth century. First focus is on changes in the distribution of paid and unpaid work tasks over the period 1965-2003, looking also at the implications for free time and personal care given the valuable "zero-sum" property of time?so that if time on one activity (like work) increases or decreases, it must be "zero-ed out" by parallel decreases or increases in other activities.

The Princeton team has generated a great body of diverse evidence on the meaning of daily life, putting it at the center of new measures of the quality of life (QOL) in a society. In their comparison of QOL in France and America, they have taken a bold and controversial step in cross-national research, one in which many scholars would argue that we still haven't been able to make sense of subjective indicators within a single country. However, they strengthen their research by using multiple measures, and cross-checking their results with earlier national surveys, to show that rather much the same findings hold in both countries (for women anyway). Unfortunately, they did not include men in these comparisons, but most QOL studies do not find large gender differences on these types of questions. Their historical integration of affective responses with time-diary activity for 1965 2005 in Fig. 2 is similarly impressive as a measure of how much the daily lives of men and women are improving (or not in this case). In this way, it reinforces most QOL analyses indicating little improvement over a 40-year period in which there has been significant gains in people's economic well-being (Robinson & Land 2008). However, there are two concerns about their research I would like to highlight. First, as Tom Juster's response above brought out, the research approach is not new and second and more importantly, it's not clear that dismissing the general measures in favor of diary ratings is justified, even in the face of their several studies comparing the two. The main evidence to the contrary comes from time-diary studies that cover the com plete spectrum of daily activity. Table 1 below reviews these earlier data from diary studies done 20-30 years ago, both national probability surveys that first examined how people rated their day's activities. It first needs to be noted that the two studies employed different methodologies for rating daily activity. The first 1975 University of Michigan study on the right, done by Juster and Stafford, asked respondents to rate how much they generally enjoyed the spe cific activities on the right side of Table 1 ("Work", Sleep", etc.). The second 1985 University of Maryland study took the Princeton team approach, as shown on the left side of Table 1. It used the same 0-10 enjoyment scale as in the Michigan study, but

Little attention in the quality-of-life literature has been paid to data on the daily activity patterns of happy and less happy people. Using ratings-scale information from time-diary studies, this article examines the hypothesis that people who describe themselves as happier engage in certain activities more than those who describe themselves as less happy. Based on 34 years of data collected by the General Social Survey (GSS) on social activities and media usage, it is found that people who are happy report being more active in most social activities, in religion and in newspaper reading. On the other hand, happier people report less time watching television, a relation that holds after control for education, marital status and other predictors of happiness. The need to replicate these findings using panel data is highlighted.

In order to track social change during a period of the rapid advances brought about by new information technologies (IT), a targeted module of IT-relevant and Internet questions was added to the 2000, 2002 and 2004 samples of the General Social Survey (GSS). The general issue inherent in and guiding the questions asked (as well as the analyses conducted) is whether IT functions to displace or expand various daily activities. In general, Internet use was not correlated with lower use of other personal communications or mass communications media—nor with lower levels of other social activities like church attendance or arts participation. In many cases the Internet was associated with increased use of other media or activities. Respondents who spend the most time on the Internet did report fewer social visits by relatives and neighbors, and perhaps less frequent sexual intercourse, but more visits with friends, compared to those who spent no time on the Internet.

This article examines recent U.S. Census Bureau data to test the hypothesis that the diffusion of the Internet is becoming more rather than less polarized by family income in the United States. Using multiple logistic regression and other odds-based analyses to assess Internet access in the United States from 1997 to 2003, this analysis finds that the odds of access increased most rapidly for individuals at highest family income levels and most slowly for individuals with the lowest income levels. These differential rates of diffusion, combined with an overall slowing of the diffusion of Internet use since 2001, suggest that it may be 2009 before a majority of lowestincome Americans use the Internet. The slow diffusion among low-income groups is not apparent in comparable assessments of Internet diffusion in European countries.

This article examines trends in divorce attitudes of young adult women in the United States by educational attainment from 1974 to 2002. Women with 4-year college degrees, who previously had the most permissive attitudes toward divorce, have become more restrictive in their attitudes toward divorce than high school graduates and women with some college education, whereas women with no high school diplomas have increasingly permissive attitudes toward divorce. We examine this educational crossover in divorce attitudes in the context of variables correlated with women's educational attainment, including family attitudes and religion, income and occupational prestige, and family structure. We conclude that the educational crossover in divorce attitudes is associated most strongly with work and family structure variables.

In this paper I examine the evolving association between educational attainment and the timing of births. In the late 1970s, women with four-year college degrees had lower first birth rates before age 30 than women with less education, but rates of first births were similar for the two groups after age 30. From the 1970s to the 1990s, first birth rates decreased before age 30 for all women, but increased after age 30 only for women with four-year college degrees. Parity 2 birth rates also increased for college graduates with a first birth after age 30. These results document widening educational differences in fertility timing between 1975 and 1995, which may reflect period changes at later ages in women’s work and family lives.

Reflecting time’s importance in everyday living and decision-making, government and academic researchers from most Western countries are collecting full 24-h time-diary data to monitor and understand how daily life differs across demographic groups, across decades, and across countries. Despite its far greater costs than simple respondent time estimates, it is argued that the diary provides a more comprehensive and accurate basis for generating national accounts of time spent working, doing housework, caring for children, caring for oneself, traveling, TV viewing, and on all the other activities that occur in free time. Diaries can also provide data on multitasking, interacting with others, and the location and timing of daily activities. For that reason, extensive diary data are now being collected on an ongoing basis by the American Time-Use Survey (ATUS) and by more than 25 other counties via the Multinational Time-Use Survey (MTUS). These diary data are being standardized and archived at the University of Oxford. In order to provide greater insight into the psychological meaning of these activities for national accounts, supplemental data are also being collected on the subjective properties of diary activities, such as activity enjoyment, tempo, purpose, and output. Several aspects, results, and conclusions from previous research are reviewed, in the context of subjective time aspects needed to provide insight into the larger meaning of daily activity.

This paper outlines decomposition methods for assessing how exposure affects prevalence and cumulative relative risk. Let x denote a vector of exogenous covariates and suppose that a single dimension of time t governs two event processes T(1) and T(2). If the occurrence of the event T(1) determines entry into the risk of the event T(2), then subgroup variation in T(1) will affect the prevalence T(2), even if subgroups in the population are otherwise identical. Although researchers often acknowledge this phenomenon, the literature has not provided procedures to assess the magnitude of an exposure effect of T(1) on the prevalence of T(2). We derive decompositions that assess how variation in exposure generated by direct and indirect effects of the covariates x affect measures of absolute and relative prevalence of T(2). We employ a parametric but highly flexible specification for baseline hazard for the T(1) and T(2) processes and use the resulting parametric proportional hazard model to illustrate the direct and indirect effects of family structure when T(1) is age at first sexual intercourse and T(2) is age at a premarital first birth for data on a cohort of nonhispanic white U.S. women.

Dans cet article, les AA. analysent les travaux de S. Kanazawa concerant le comportement des electeurs suivant la theorie du choix rationnel. Les AA. adressent ici deux critiques methodologiques du modele statistique de Kanazawa

This paper evaluates the data quality of two demographic variables in light of hypotheses on respondent recall from the literature on survey methodology. An emerging consensus in this literature is that recall of the timing of an event declines with recall duration unless the dating of an event is frequently "rehearsed." We provide empirical evidence consistent with this hypothesis by assessing the quality of demographic data on two event history variables as supplied by female respondents. A first outcome concerns the interval between a first and second birth. We assess examine birth intervals using birth registration data from the Vital Statistics on Natality (VSN) and individual-level survey data from the 1990 June Current Population Survey (CPS), the 1979-93 waves of the National Longitudinal Survey of Youth (NLSY), and the 1988 National Survey of Family Growth (NSFG). Overall, we find relatively little variation in the quality of birth interval data across these four surveys, with onie exception-CPS data in which responses have been allocated. A second demographic variable is age at first sexual intercourse. We engage in several analyses of this variable. First, we use NLSY data to analyze discrepan