Diversification preferences in the theory of choice

Diversification represents the idea of choosing variety over uniformity. Within the theory of choice, desirability of diversification is axiomatized as preference for a convex combination of choices that are equivalently ranked. This corresponds to the notion of risk aversion when one assumes the von Neumann–Morgenstern expected utility model, but the equivalence fails to hold in other models. This paper analyzes axiomatizations of the concept of diversification and their relationship to the related notions of risk aversion and convex preferences within different choice theoretic models. Implications of these notions on portfolio choice are discussed. We cover model-independent diversification preferences, preferences within models of choice under risk, including expected utility theory and the more general rank-dependent expected utility theory, as well as models of choice under uncertainty axiomatized via Choquet expected utility theory. Remarks on interpretations of diversification preferences within models of behavioral choice are given in the conclusion.     

Multiprofessional Cooperation and Accountability Pressures

Abstract

This article examines how multiprofessional healthcare teams, working as a post-New Public Management (post-NPM) reform, respond to accountability pressure resulting from the implementation of NPM reforms. The team members use three strategies to respond to this pressure: responsibility avoiding that results in conflict; responsibility ignoring that results in parallel work and responsibility sharing that results in cooperation. Depending on how the professionals respond to different contextual factors, the choice of strategies can either foster or inhibit cooperation in multiprofessional teams. Achieving holistic patient care is threatened when accountability pressure increases for teams that have not yet developed their internal routines of cooperation.     

Sealed bid auctions versus ascending bid auctions: an experimental study

This paper considers two multi-item auction formats (ascending and sealed bid) which both identify the minimum Walrasian equilibrium prices and where truthful preference revelation constitutes an equilibrium. Even though these auction formats share many theoretical properties, there are behavioral aspects that are not easily captured. To explore this issue in more detail, this paper experimentally investigates what role the design of the auction format has for its outcome. The results suggest that the sealed bid mechanism performs weakly better in all of the investigated measures (consistent reporting, efficiency etc.). In addition, we find that the performance of the ascending auction is increasing over time, whereas the sealed bid auction shows no such tendency.     

The role of accident theory in injury prevention - time for the pendulum to swing back

Injury prevention is a branch of safety sciences. While comprehensive theoretical developments occurred in the wider field in the last decades, little of these developments reached and influenced the injury prevention community. Instead, a clear retro trend 'back to basics' is seen among injury prevention scholars, especially to Dr William Haddon's pioneering work some 50 years ago. This paper intends to draw attention to this polarisation and discuss possible explanations. It is argued that the strong campaign against the accident concept among leading injury prevention groupings became a serious hindrance for theoretical exchange. The underlying process is interpreted in terms of a struggle for ownership over this truly interdisciplinary field of research, unfortunately at the expense of theoretical stagnation in injury prevention circles and lessened interest in collaboration from other scientific areas. This paper is written as a tribute to Professor Leif Svanstr?m and his scientific contributions, with special regard to his genuine interest in interdisciplinary research.     

When is your experience valuable? Occupation-industry transitions and self-employment success

The literature on employee spinoffs has, for a long time, stressed the importance of industry-specific skills and experiences in explaining the success of new firms. We argue that employees also develop skills that are associated with their occupation within an industry, and that success as an entrepreneur, therefore, is also contingent on the relation between the entrepreneurs’ previous occupation and the industry in which they operate as self-employed. Using matched employer-employee data, we develop a measure, occupational spin-offs, that accounts for this relation. An occupational spin-off is defined as a start-up in the most common industry, given the previous occupation of the founder. We then show that entrepreneurs starting occupational spinoffs enjoy above average income from self-employment and have longer spells as business owners.     

Empirical Evidence on the Relationship between Mobile Termination Rates and Firms' Profits

The theoretical literature on mobile termination rates (MTRs) is inconclusive on how the level of MTRs affects overall consumer charges and firms' profits. We show that when firms offer bundles with fixed included usage – a tariff structure that has become more common in recent years – an identical change in all MTRs does not affect firms' retail prices or profits. We use a panel dataset from saturated European markets to estimate the effect of MTRs on mobile operators' profits. As predicted by the theoretical model, we cannot reject the fact that firms' profits are unaffected by an identical change in all MTRs.     

A trust game in loss domain

In standard trust games, no trust is the default, and trust generates a potential gain. We investigate a reframed trust game in which full trust is default and where no trust generates a loss. We find significantly lower levels of trust and trustworthiness in the loss domain when full trust is default than in the gain domain when no trust is default. As a consequence, trust is on average profitable in the gain domain, but not in the loss domain. We also find that subjects respond more positively to higher trust in the loss domain than in the gain domain.     

Using traffic data to estimate wildlife populations

Wildlife populations are threatened worldwide by, among others, habitat fragmentation and hunting pressure. An important impediment for the large scale, national and regional, management of the populations is the difficulty to quantify population dynamics. The purpose of this study is to present a tool for such estimations which is based on available data in several countries; traffic load and traffic accidents with wildlife. An econometric model is developed, which accounts for landscape characteristics. It is applied to wild boar in Sweden, for which data on traffic load and accidents for different counties and years are available. Landscape characteristics are introduced with direct or indirect effects on population growth. The indirect landscape model gives the best statistical performance, and the results show relatively small differences in calculated intrinsic growth rate among counties but considerable differences in predicted population developments.     

An Experimental Study of Influences of Performance-Related Payments on Timing of Delegated Stock Purchases

Performance-related bonuses are important tools for investment organizations to incentivize stock traders. Yet, two experiments indicate that bonuses rewarding short-term performance may lead to worse timing of purchases. The authors propose that hyperbolic time discounting makes participants set lower aspired purchase prices for short-term (decreasing percentage) bonuses than for long-term (increasing percentage) bonuses. For this reason purchases are made earlier for decreasing than increasing percentage bonuses, earlier for decreasing than random prices, and earlier for high price volatility than for low price volatility. Neither purchases at the lowest price or highest bonus are attained. Hyperbolic time discounting may account for bubbles observed in experimental double-auction markets.     

Gender and conservation agriculture in East and Southern Africa: towards a research agenda

It is remarkable that despite wide-ranging, in-depth studies over many years, almost no conservation agriculture (CA) studies consider gender and gender relations as a potential explanatory factor for (low) adoption rates. This is important because CA demands new ways of working with the farm system. Implementation will inevitably involve a reallocation of men's and women's resources as well as having an impact upon their ability to realize their gender interests. With respect to intra-household decision-making and the distribution of benefits, CA interventions have implications for labour requirements and labour allocation, investment decisions with respect to mechanization and herbicide use, crop choice, and residue management. CA practice may impact upon the ability of households to source a wide variety of crops, wild plants, and insects and small animals for household nutrition. Gender biases in extension service design can sideline women. This paper examines the limited research to date on the interactions between CA interventions and gender in East and Southern Africa, and, based on the gaps observed, sets out a research agenda. It argues that attention to gender in CA is particularly timely given the increasing interest in CA as a means of adapting to climate change.