Same-Gender Sexual Partnering: A Re-Analysis of Trend Data

Numerous studies have been carried out to estimate the prevalence of same-gender sexual behavior. Among studies conducted in recent years, few confirm the commonly quoted figure of 10%. Yet several studies in the early 2000s indicated that the prevalence of same-gender sex may be increasing, especially among women. This article reexamines the trends identified in previous research by using General Social Survey data from 1988 to 2010 and by focusing on multiple measures of same-gender sex over time. Results indicate that for both women and men the likelihood of having had a same-gender sexual partner since age 18 continued to increase through the 2000s, but that the likelihood of having had a same-gender sexual partner in both the past year and in the past five years leveled off for women and reversed for men. Results also indicate that the percentage of people reporting a pattern of predominantly same-gender sexual behavior has neither increased nor decreased over time. A similar result was found among persons who reported being in a same-gender sexual relationship. Overall, results paint a more complex picture than prior studies in characterizing trends in same-gender sexual behavior.     

CONTRACTS AS RENT‐SEEKING DEVICES: EVIDENCE FROM GERMAN SOCCER

Recent theoretical research has identified many ways how contracts can be used as rent‐seeking devices vis‐à‐vis third parties, but there is no empirical evidence on this issue so far. To test some basic qualitative properties of this literature, we develop a theoretical and empirical framework in the context of European professional soccer where (incumbent) teams and players sign binding contracts which, however, are frequently renegotiated when other teams (entrants) want to hire the player. Because they weaken entrants in renegotiations, long‐term contracts are useful rent‐seeking devices for the contracting parties. However, they reduce the likelihood of (mutually beneficial) transfers, which generates a trade‐off in the spirit of Aghion and Bolton (1987). Using a data set from the German “Bundesliga,” our model predictions are broadly confirmed. (JEL L14, J63, L40, L83)     

ON THE EXTERNAL VALIDITY OF LABORATORY TAX COMPLIANCE EXPERIMENTS

An essential issue for laboratory experiments to inform policy debates is the “external validity” of the experimental results; that is, does behavior in the laboratory apply to behavior that occurs in the naturally occurring world? We examine this issue of external validity in the specific context of laboratory experiments on tax compliance, using two different types of evidence. We find that the behavioral patterns of subjects in the laboratory conform to those of individuals making a similar decision in naturally occurring settings. We also find that the behavioral responses of students are largely the same as those of nonstudents in identical experiments (JEL C9, H0, H3)     

Politics beyond identity: reconsidering the civil rights movement in Northern Ireland

The Northern Irish civil rights movement, like other minority or subaltern struggles, has been interpreted in terms of the national minority’s struggle for state recognition. Such frameworks emphasise the importance of identity in political conflict and tend to assume the state as guarantor of the recognition of identity. The difficulty here is that political possibilities that exceed the terms of identity and the state are obscured. Moreover, the interpretation of the Northern Irish conflict in these terms forms part of the consociational approach to conflict resolution which operates as normative underpinning to the post-conflict state. This article provides an alternative interpretation of the political significance of the civil rights movement. Rather than assuming the analytical usefulness and political significance of identity, I seek to trace the tension between identity and disidentification within the movement, drawing attention to the ways in which activists were aware of, and sought to respond to, the dangers of identity politics.     

A useful approach to identify the multicollinearity in the presence of outliers

The presence of outliers in the data sets affects the structure of multicollinearity which arises from a high degree of correlation between explanatory variables in a linear regression analysis. This affect could be seen as an increase or decrease in the diagnostics used to determine multicollinearity. Thus, the cases of outliers reduce the reliability of diagnostics such as variance inflation factors, condition numbers and variance decomposition proportions. In this study, we propose to use a robust estimation of the correlation matrix obtained by the minimum covariance determinant method to determine the diagnostics of multicollinearity in the presence of outliers. As a result, the present paper demonstrates that the diagnostics of multicollinearity obtained by the robust estimation of the correlation matrix are more reliable in the presence of outliers.     

Time to Diagnosis: Accounting for Differential Endpoint Follow-up in Multi-Cohort Studies

Cox regression is widely used to analyze discrete survival time data. Differential endpoint follow-up across sub-cohorts where distribution of a covariate varies may cause typical estimators to be biased or inefficient. We demonstrate that with Cardiovascular Health Study data for incident type 2 diabetes. Two cohorts with extremely different race distribution have differential follow-up for fasting glucose levels. We study various scenarios of Cox regression. We suggest an alternative approach, Poisson generalized estimating equations with an offset to accommodate the differential follow-up. We use simulations to contrast the methods.     

Combinatorial Equivalence of Fractional Factorial Designs

Two symmetrical fractional factorial designs are said to be combinatorially equivalent if one design can be obtained from another by reordering the runs, relabeling the factors and relabeling the levels of one or more factors. This article presents concepts of ordered distance frequency matrix, distance frequency vector, and reduced distance frequency vector for a design. Necessary conditions for two designs to be combinatorial equivalent based on these concepts are presented. A new algorithm based on the results obtained is proposed to check combinatorial non-equivalence of two factorial designs and several illustrating examples are provided.