POPAN-4: enhancements to a system for the analysis of mark-recapture data from open populations

We describe recent developments in the POPAN system for the analysis of mark-recapture data from Jolly-Seber type experiments. The previous versions (POPAN-3 for SUN/OS workstations and POPAN-PC for IBM-PC running DOS or Windows) included general statistics gathering and testing procedures, a wide range of analysis options for estimating population abundance, survival and birth parameters, and a general simulation capability. POPAN-4 adds a very general procedure for fitting constrained models based on a new unified theory for Jolly-Seber models. Users can impose constraints on capture, survival and birth rates over time and/or across attribute groups (e.g. sex or age groups) and can model these rates using covariate models involving auxiliary variables (e.g. sampling effort).     

Fitting Weibull duration models with random effects

Duration time models often should include correlated failure times, due to clustered data. These random effects hierarchical models sometimes are called frailty models when used for survival analyses. The data analyzed here involve such correlations because patient level outcomes (the times until graft failure following kidney transplantation) are observed, but patients are clustered in different transplant centers. We describe fitting such models by combining two kinds of software, one for parametric survival regression models, and the other for doing Poisson regression in a hierarchical setting. The latter is implemented by using PRIMM (Poisson Regression and Interactive Multilevel Modeling) methods and software (Christiansen & Morris, 1994a). An illustrative example for profiling data is included withk=11 kidney transplant centers andN=412 patients.     

Long-term social development of Hungary,measured by social indicators

Social indicators of social structure, urbanisation, level of living and social mobility chances are used to study the development of Hungarian society from the period of capitalist society to the present. The impact of socialist transformations, as well as the influences of the new economic and social conditions appearing in the second half of the 1960's and leading to the economic reforms are especially investigated. Modernization, the decline of inequalities of income and of social mobility opportunities characterized the socialist transformations. Since the mid-60's new tendencies are emerging that need careful investigation.     

Service tasks of board of directors: A literature review and research agenda in an era of new governance practices

In their seminal review article on board of directors, Johnson, Daily, and Ellstrand (1996) distinguished between the control, service, and resource dependence tasks of the board and called for a stronger focus on board service tasks. Following this call, service tasks of boards have been subject to increased scholarly attention, with new theoretical perspectives and methods introduced. This paper aims at presenting the current state of research on board service tasks, departing from, and building on, the contribution of Johnson and colleagues. In doing so, we employ an Input-Process-Output-Context framework and craft an agenda for how future research could accommodate new governance practices and progress the field. Our review is relevant and timely as studies on the subject are gaining traction both in corporate governance and general management journals. Furthermore, our review on board service tasks proposes new alternative approaches to studying corporate governance which are especially appropriate in times in which a rethink of corporate governance frameworks and concepts is urgently needed.     

A Novel Approach to Chemical Mixture Risk Assessment—Linking Data from Population‐Based Epidemiology and Experimental Animal Tests

Humans are continuously exposed to chemicals with suspected or proven endocrine disrupting chemicals (EDCs). Risk management of EDCs presents a major unmet challenge because the available data for adverse health effects are generated by examining one compound at a time, whereas real‐life exposures are to mixtures of chemicals. In this work, we integrate epidemiological and experimental evidence toward a whole mixture strategy for risk assessment. To illustrate, we conduct the following four steps in a case study: (1) identification of single EDCs (“bad actors”)—measured in prenatal blood/urine in the SELMA study—that are associated with a shorter anogenital distance (AGD) in baby boys; (2) definition and construction of a “typical” mixture consisting of the “bad actors” identified in Step 1; (3) experimentally testing this mixture in an in vivo animal model to estimate a dose–response relationship and determine a point of departure (i.e., reference dose [RfD]) associated with an adverse health outcome; and (4) use a statistical measure of “sufficient similarity” to compare the experimental RfD (from Step 3) to the exposure measured in the human population and generate a “similar mixture risk indicator” (SMRI). The objective of this exercise is to generate a proof of concept for the systematic integration of epidemiological and experimental evidence with mixture risk assessment strategies. Using a whole mixture approach, we could find a higher rate of pregnant women under risk (13%) when comparing with the data from more traditional models of additivity (3%), or a compound‐by‐compound strategy (1.6%).     

Organizational Reputation and the Securities and Exchange Commission's Failed Regulatory Revolution

When do regulatory innovations fail? I provide a novel organizations‐based answer to this question by developing an institutional‐reputational approach to regulatory politics. Regulators cannot hope to monitor the vast majority of market activities, so they must rely on the regulated to condition their behavior on the regulator's reputation: beliefs and expectations concerning the regulator's goals and capabilities. Regulators thus pursue daily activities while being mindful of how these activities will shape their reputation and thus their ability to achieve future goals. However, even long‐standing reputations are rendered fragile when rival actors use the organization's reputation to cross‐purposes. Thus, while reputation represents a major source of power, reputation also proves fragile when organizations face conflicting reputational demands. The fragility of reputations provides a novel explanation of an understudied phenomenon: failed regulatory revolutions. I develop this theory through the analysis of innovative Securities and Exchange Commission activity in disclosure law following the Watergate investigation.