Beliebt und immer beliebter? Fernsehen und Freizeit in Deutschland 1987�C2007

The hypothesis that Germans devote an ever bigger share of their increasing leisure time to television is justified by a comparison with further leisure activities: Television exceeds all these??except the internet??by its increasing supply and increasing differentiation. This hypothesis is examined using the so-called Media-Analysen 1987?C2007. It is confirmed by regression analyses of the absolute and relative television viewing time on time points or on the extent and the differentiation of television supply, controlling for opportunities and preferences as well as cohort membership, region and gender. Thus, television does not lose leisure shares to new media, but crowds out old leisure pastimes.     

The Productivity Advantages of Large Cities: Distinguishing Agglomeration From Firm Selection

Firms are more productive, on average, in larger cities. Two main explanations have been offered: firm selection (larger cities toughen competition, allowing only the most productive to survive) and agglomeration economies (larger cities promote interactions that increase productivity), possibly reinforced by localized natural advantage. To distinguish between them, we nest a generalized version of a tractable firm selection model and a standard model of agglomeration. Stronger selection in larger cities left‐truncates the productivity distribution, whereas stronger agglomeration right‐shifts and dilates the distribution. Using this prediction, French establishment‐level data, and a new quantile approach, we show that firm selection cannot explain spatial productivity differences. This result holds across sectors, city size thresholds, establishment samples, and area definitions.     

Parent and Peer Effects on Delinquency-related Violence and Dating Violence: A Test of Two Mediational Models

Drawing on two complementary process models of violence, i.e., social cognitive theory and rejection sensitivity theory, the goal of the present study was (1) to examine the unique effects of parents and peers on boys’ violent behavior in delinquency‐related contexts and in dating relationships, (2) to assess the mediating processes underlying these links, and (3) to test whether these processes operate in the same way for delinquency‐related violence and dating violence. Based on a sample of 336 boys, results showed that problematic experiences with parents and with peers each predicted subsequent violence, both in delinquency‐related and in dating‐related contexts. However, the contributions of the social cognitive model and the rejection sensitivity model in explaining these links varied somewhat depending on the situational context of the violent behavior. The implications of the similarities and specificities in the risk factors and pathways leading to delinquency‐related violence and dating violence are discussed.     

Methodologic challenges of e-health research

In this article, research-based strategies used in a web-based study to assess the impact of participation in cancer-related mailing lists on cancer survivors and caregivers are highlighted. The paper presents alternative methods of measuring response rates in Internet surveys. Response rate estimation, based on American Association for Public Opinion Research guidelines, ranged between 15% and 24.9% for the study. Several strategies were implemented to increase survey participation and reduce item nonresponse. Few participants opted for a telephone survey as an alternative to a web-administered design (mixed-mode administration). Using time-stamp data to diagnose places in the questionnaire where respondents prematurely exited or broke off survey participation, we were able to decrease premature break offs. A lottery was also implemented to increase response rates. The experience of obtaining institutional review board approval for the lottery is also described. Preliminary data indicate slight increases in response rates subsequent to implementing the lottery.