Changing compatibility of cohabitation and childbearing between young British women born in 1958 and 1970

We investigate the effect of parenthood on whether non-marital unions led to marriage or parting for two cohorts of British women when they were aged between 16 and 29. We compare the effect of conceptions leading to births and the presence and characteristics of children on the odds that a cohabitation was dissolved, or that it was converted to marriage, for women born in 1958 and 1970. A multilevel, multiprocess, competing-risks model allows for multiple cohabitation per woman and endogeneity of fertility status. We find that cohabiting couples' response to impending parenthood and the presence of children changed over time. In particular, the proportion of cohabiting couples who married before a birth decreased and, in the 1970 cohort only, the risk of dissolution declined during pregnancy. There is also evidence that the presence of a child cemented a cohabiting union for women from the 1970, but not the earlier, cohort.     

Tests for an end-of-sample bubble in financial time series

ABSTRACT

In this paper, we examine the issue of detecting explosive behavior in economic and financial time series when an explosive episode is both ongoing at the end of the sample and of finite length. We propose a testing strategy based on a subsampling method in which a suitable test statistic is calculated on a finite number of end-of-sample observations, with a critical value obtained using subsample test statistics calculated on the remaining observations. This approach also has the practical advantage that, by virtue of how the critical values are obtained, it can deliver tests which are robust to, among other things, conditional heteroskedasticity and serial correlation in the driving shocks. We also explore modifications of the raw statistics to account for unconditional heteroskedasticity using studentization and a White-type correction. We evaluate the finite sample size and power properties of our proposed procedures and find that they offer promising levels of power, suggesting the possibility for earlier detection of end-of-sample bubble episodes compared to existing procedures.     

Granite and green: thinking beyond surface in place studies

Through their dense range of empirical sortings, Kaufman and Kaliner, in this issue of Theory and Society, are effective in showing mechanisms through which places replicate themselves over time, but also in how their cultural and economic profiles can shift. Their work points to the utility of matched comparisons of historical interaction, both symbolic and material, as tool for understanding trajectories of stability and change.     

ON THE INEFFECTIVE EDUCATION OF DECISION SCIENTISTS

There is general agreement that the training of decision scientists during the past ten years has left much to be desired. This note presents nine rules relating to the fundamental reasons for the failure of training programs, along with suggestions for improving the present state of affairs.     

MANAGING THE DECISION SCIENCE TECHNOLOGY: A CASE FOR ETHICAL ANALYSIS?*

After ten years of rapid, if sometimes chaotic growth, it is time to reflect upon where Decision Sciences is headed. At stake are the essential questions of (1) should the growth of the discipline be managed, and if so (2) how should it be managed and who should do the managing? I argue that the growth of the discipline should be managed rather than be dictated by the technological imperative that states that any envisioned application of quantitative methods should be implemented. Moreover, I argue that, since to a large degree the implementation decision is an ethical question, the individual decision scientist must ultimately be held accountable. Finally, I suggest that Glenn Stassen's social ethic paradigm may be a useful vehicle for resolving intradiscipline conflicts. These abstract ideas are concretized by examining the growth of the area of artificial intelligence.     

CRACKING THE CORNFIELDS: Recruiting Illicit Stimulant Drug Users in Rural Ohio

This article describes the process of recruiting research subjects for a natural history study of illicit stimulant use in rural Ohio using respondent-driven sampling and ethnographic methods. Participant observation, qualitative interviews, and focus groups were used to establish the project and to evaluate and modify the sampling process as it unfolded. We outline the steps taken in several different rural counties, using ethnographic data to illustrate local differences and obstacles that were faced. The article concludes that respondent-driven sampling is a promising method for identifying and recruiting members of hidden populations in rural areas. However, adequate time must be allotted to establish ethnographic footholds and to reach various networks in separate communities.