On the functional form of temporal discounting: An optimized adaptive test

The tendency to discount the value of future rewards has become one of the best-studied constructs in the behavioral sciences. Although hyperbolic discounting remains the dominant quantitative characterization of this phenomenon, a variety of models have been proposed and consensus around the one that most accurately describes behavior has been elusive. To help bring some clarity to this issue, we propose an Adaptive Design Optimization (ADO) method for fitting and comparing models of temporal discounting. We then conduct an ADO experiment aimed at discriminating among six popular models of temporal discounting. Rather than supporting a single underlying model, our results show that each model is inadequate in some way to describe the full range of behavior exhibited across subjects. The precision of results provided by ADO further identify specific properties of models, such as accommodating both increasing and decreasing impatience, that are mandatory to describe temporal discounting broadly.     

Markov Perfect Industry Dynamics With Many Firms

We propose an approximation method for analyzing Ericson and Pakes (1995)‐style dynamic models of imperfect competition. We define a new equilibrium concept that we call oblivious equilibrium, in which each firm is assumed to make decisions based only on its own state and knowledge of the long‐run average industry state, but where firms ignore current information about competitors' states. The great advantage of oblivious equilibria is that they are much easier to compute than are Markov perfect equilibria. Moreover, we show that, as the market becomes large, if the equilibrium distribution of firm states obeys a certain “light‐tail” condition, then oblivious equilibria closely approximate Markov perfect equilibria. This theorem justifies using oblivious equilibria to analyze Markov perfect industry dynamics in Ericson and Pakes (1995)‐style models with many firms.     

What cultural values influence American public relations practitioners?

This paper advances a cultural approach to public relations research and practice through the extension of Hofstede’s cultural dimensions to Grunig’s models of public relations. This study tested a quantitative instrument that links societal culture, corporate culture, and the public relations communication of American practitioners. Two findings emerged from this study. First, American practitioners continue to practice one-way models of public relations even when their organizations may not dictate one-way communication with publics. And second, public relations practitioners who have collectivistic values tend to practice two-way models of public relations.Gabriel Vasquez is an assistant professor in the School of Communication, University of Houston, TX. Maureen Taylor is an assistant professor in the School of Communication, Information, and Library Studies at Rutgers University, NJ.     

Fitting a Semi-Parametric Mixture Model for Competing Risks in Survival Data

A model for survival analysis is studied that is relevant for samples which are subject to multiple types of failure. In comparison with a more standard approach, through the appropriate use of hazard functions and transition probabilities, the model allows for a more accurate study of cause-specific failure with regard to both the timing and type of failure. A semiparametric specification of a mixture model is employed that is able to adjust for concomitant variables and allows for the assessment of their effects on the probabilities of eventual causes of failure through a generalized logistic model, and their effects on the corresponding conditional hazard functions by employing the Cox proportional hazards model. A carefully formulated estimation procedure is presented that uses an EM algorithm based on a profile likelihood construction. The methods discussed, which could also be used for reliability analysis, are applied to a prostate cancer data set.     

From 'human being' to 'social subject': "unfreezing" ergonomics and the implications for understanding and intervening health-disease process

Ergonomics has been successful in increasing productivity and comfort in the work arena. It has also contributed to reducing occupational accidents. Despite this, ergonomics is frequently limited to understanding the health-disease process related to human-technology interactions, as this process is more complex than what can be understood from an ergonomic evaluation. Recognising this limit, this work ontologically and epistemologically contrasts the notions of 'human being' and 'social subject', and concludes that the study object of ergonomics, or human-technology interaction, greatly depends on social aspects that nowadays are not tackled explicitly: route (history), project, structure, agency, motivations and power. It also analyses how participatory ergonomics tacitly includes many of these aspects, including some implications that the change of notion, from 'human being' to 'social subject', brings to the understanding of the health-disease process and the reduction of associated risks during human activities.     

A mixed-method exploration of functioning in Safe Schools/Healthy Students partnerships

This paper presents a mixed-method approach to measuring the functioning of Safe Schools/Healthy Students (SS/HS) Initiative partnerships. The SS/HS national evaluation team developed a survey to collect partners’ perceptions of functioning within SS/HS partnerships. Average partnership functioning scores were used to rank each site from lowest to highest. Sites with the most favorable perceptions of partnership functioning were defined as having average scores in the top 10% (n = 10) and sites with the least favorable perceptions of partnership functioning were defined as having average scores in the bottom 10% (n = 10). Qualitative data for these 20 sites were inductively open coded for emergent themes and analyzed for patterns using grounded theory approach. Six themes emerged that distinguished sites reporting the most favorable and least favorable perceptions of partnership functioning: partner engagement, facilitators, barriers, shared decision making, partnership structure, and sustainability. Sites reporting the most favorable perceptions of partnership functioning effectively utilized collaboration processes that facilitate coalition building, such as shared decision making, effective communication, and developing a clearly defined structure. Qualitative themes from this analysis provide evidence of validity for the partnership functioning scale used and illustrate distinguishing features between sites with the most favorable and least favorable perceptions of partnership functioning.     

ARE THE DISABLED LESS LOSS AVERSE? EVIDENCE FROM A NATURAL POLICY EXPERIMENT

Research findings show that disabled persons often develop physical and psychological mechanisms to compensate for disabilities. Coping mechanisms may not be limited to the psychophysiological domain and may extend to cognitive bias and loss aversion. In this study, we apply unique microdata from a natural policy experiment to assess the role of loss aversion in home purchase among nondisabled and disabled households. Results of survival analysis indicate that the physically disabled are substantially less loss averse in home purchase. Furthermore, loss aversion varies with other population characteristics and attenuates with degree of disability. Findings provide new evidence of diminished cognitive bias and more rational economic decision‐making among the physically disabled. (JEL D03, C9, R38)     

An empirical assessment of the wage premium for American veterans of World War II

This paper examines U.S. census data from 1960 to 1980 to assess the relative wages of WWII veteran and non-veteran men. Our analysis reveals that a significant portion wage gap between veterans and non-veterans (the “veteran wage premium”) is due primarily to differences in education, work experience and other socioeconomic characteristics. Our findings are consistent with the notion that greater human capital, due perhaps to the selection process for military service, or to the post-war benefits provided by the GI Bill, helped contribute to the remarkable post-war labor market success of American veterans. To a lesser extent, veterans may also have benefited from preferential labor market treatment, or from intangible aspects of military experience that enhanced their returns to earnings-related characteristics.     

The variability of individual charitable giving in the US

Using five-year panel data, this study examines the various dimensions of the variability of individual charitable contributions at all income levels: the variation in the generosity of individuals and the variability of the individuals' giving over a five-year period. The study finds considerable variability of both kinds. One finding is that the variability of generosity is substantially greater at the higher income levels. Another finding is that variability is substantially less pronounced by observing a five-year period of an individual's generosity than by observing annual behaviour. One consequence is that a relatively small proportion of donors account for a large proportion of total giving. The popular reputation of the wealthy for generosity is actually due to the exceptional generosity of a minority rather than widespread generosity among the wealthy. Differences in generosity and variability of giving over time are both more pronounced among high-income donors. Results of the study have implications for research on charitable giving, for predicting the effects of tax policy changes on giving, and for fund-raising.The authors wish to acknowledge the valuable comments of Charles Clotfelter, Susan Rose-Ackerman, Jerry Schiff, Eugene Steuerle and participants in a conference on the non-profit sector at the Center for the Study of Philanthropy and Voluntarism at Duke University. The research was supported in part by Yale University's Institution for Social and Policy Studies (Program on Non-Profit Organisations). The views expressed are those of the authors alone and do not represent the views or policies of the above institutions or individuals.