A Mathematical Programming Approach to Production Decisions in the Emerging Aquaculture Industry

The creation of new food sources is an important advancement in the search for solutions to food shortages in both developing and underdeveloped countries. Aquaculture, the production of aquatic animals under controlled conditions, offers exciting new possibilities for alternative protein sources in a wide variety of locales. This paper presents a mathematical programming model designed to aid the manager of an aquaculture facility in production scheduling and the evaluation of new technologies in this rapidly changing environment.     

TRUST,RECIPROCITY, AND RULES

Many economic interactions rely on trust and trust violations can have serious economic consequences. Simple minimum standard rules are attractive because they prevent egregious trust violations. However, they may undermine more trusting and reciprocal (trustworthy) behavior that otherwise would have occurred, leading to worse outcomes. In an experimental trust game, we test the efficacy of exogenously imposed minimum standard rules. Rules damage trust and reciprocity, reducing economic welfare. While sufficiently restrictive rules restore welfare, trust and reciprocity never return. Results indicate that participants are concerned about payoffs while also using the game to learn about trust and trustworthiness of others. (JEL C72, C90, D63, D64, L51)     

Applying functional data analysis to assess tele-interpersonal psychotherapy's efficacy to reduce depression

The use of parametric linear mixed models and generalized linear mixed models to analyze longitudinal data collected during randomized control trials (RCT) is conventional. The application of these methods, however, is restricted due to various assumptions required by these models. When the number of observations per subject is sufficiently large, and individual trajectories are noisy, functional data analysis (FDA) methods serve as an alternative to parametric longitudinal data analysis techniques. However, the use of FDA in RCTs is rare. In this paper, the effectiveness of FDA and linear mixed models (LMMs) was compared by analyzing data from rural persons living with HIV and comorbid depression enrolled in a depression treatment randomized clinical trial. Interactive voice response systems were used for weekly administrations of the 10-item Self-Administered Depression Scale (SADS) over 41 weeks. Functional principal component analysis and functional regression analysis methods detected a statistically significant difference in SADS between telphone-administered interpersonal psychotherapy (tele-IPT) and controls but linear mixed effects model results did not. Additional simulation studies were conducted to compare FDA and LMMs under a different nonlinear trajectory assumption. In this clinical trial with sufficient per subject measured outcomes and individual trajectories that are noisy and nonlinear, we found FDA methods to be a better alternative to LMMs.     

Armed robbery and the meanings of money

In this study, we investigate the meanings active armed robbers give to money before, during, and after their crimes and how these meanings shape their offending. We do so by examining interviews undertaken from 1994 to 1995 with robbers in St. Louis, Missouri, USA. Prior to their robberies, the interviewees' desperation leads them to define money as essential to survival. Immediately following robberies and in looking back on them, they come to view this essential money in other ways as well—as too time-consuming to get, as “easy,” or as guilt-free. These meanings facilitate the contradictory way robbers see money as “fast” after offences. We discuss how these shifting meanings of money shape and are shaped by robbers' structural positions, cultural outlooks, and social relations. In doing so, we also help to explain how the shifting meanings of money play into criminogenic cycles of predatory offending.     

Computing equilibrium in network utility-sharing and discrete election games

Journal of Combinatorial Optimization - This paper studies the computation of pure Nash equilibrium (PNE) in network utility-sharing and discretized Hotelling–Downs games, and the interplay...