The effect of latency variables on repeated measures inference applied to the measurement of risk-taking as a function of psychopathy

In numerous psychology studies, subjects are asked to perform some task a number of times, T. The effect of the choice of T on the associated inference, however, is usually not assessed. We investigate the appropriate choice of T empirically by using data collected in a study on the relationship between psychopathy and risk-taking in 90 inner city drug users enrolled in a residential treatment program. We show that, when studying this relationship, the latency variable usually discarded from the analysis behaves exponentially allowing a natural division of the study period 1, . . . , T into two distinct subperiods. These subperiods yield significantly different results—in the early period only (which we call “reactive”), subjects with high psychopathy scores exhibit lower sensitivity to reward and punishment in our risk taking experiment. The later period (which we call “stable”) shows no relationship between sensitivity to reward and punishment and psychopathic tendencies.     

Incomplete Credit Markets and Commodity Marketing Behaviour

We use a simple theoretical model of seasonal market participation in the presence of liquidity constraints and transaction costs to explain the ‘sell low, buy high’ puzzle in which some households do not take advantage of inter‐temporal price arbitrage through storage and sell output postharvest at prices lower than observed prices for purchases in the subsequent lean season. We test our model with data from western Kenya using maximum likelihood estimation of a multivariate sample selection model of market participation. Access to off‐farm income and credit indeed seem to influence crop sales and purchase behaviours in a manner consistent with the hypothesised patterns.     

HEDGING STRATEGIES AND MINIMAL VARIANCE PORTFOLIOS FOR EUROPEAN AND EXOTIC OPTIONS IN A LÉVY MARKET

This paper presents hedging strategies for European and exotic options in a Lévy market. By applying Taylor’s theorem, dynamic hedging portfolios are constructed under different market assumptions, such as the existence of power jump assets or moment swaps. In the case of European options or baskets of European options, static hedging is implemented. It is shown that perfect hedging can be achieved. Delta and gamma hedging strategies are extended to higher moment hedging by investing in other traded derivatives depending on the same underlying asset. This development is of practical importance as such other derivatives might be readily available. Moment swaps or power jump assets are not typically liquidly traded. It is shown how minimal variance portfolios can be used to hedge the higher order terms in a Taylor expansion of the pricing function, investing only in a risk‐free bank account, the underlying asset, and potentially variance swaps. The numerical algorithms and performance of the hedging strategies are presented, showing the practical utility of the derived results.     

Connectivity and work dominance: Panacea or pariah?

Does technologically-supported work connectivity help young managers and professionals under the age of 45 deal with the pressing demands of their work, or does the presence of work-connecting technologies exacerbate the tendencies of this talent force to engage in more work and longer working hours? Utilizing both surveys and follow-up focus group interactions, this study found that while work-connecting technologies permitted a greater range of options regarding when and where work was done, this same connectivity provided constant availability to work and often drove expectations that more must be done, thereby increasing the likelihood of longer work hours and—surprisingly—leading to a diminished sense of flexibility. Study participants offer insights regarding the thought processes behind these outcomes. Perspectives on how emerging leaders and their organizations can effectively manage and achieve the potential of enhanced connectivity are provided. A four-phased approach is recommended. First, we discuss key cultural dynamics. Second, the role of organizational expectations and practices is emphasized. Third, we consider a set of responsibilities for organizational leaders, whose actions and cues provide the most vivid clarity for young managers attempting to decide where to draw the work/life balance line. Finally, the challenge and responsibility of personal accountability is presented. Consideration of a work paradigm that reorients our thinking about traditional “face time,” and strives to bridge the gap between the potential and pervasive impact of work-connecting technologies, is also included.     

Resource flows through the multilateral system for food and agriculture : Trends of the decade

The tenth session of the World Food Council in Addis Ababa, Ethiopia, held on 11–15 June 1984, undertook an assessment of international activities in the decade since 1974 for meeting the World Food Conference objectives of improving the global food system and overcoming the blight of world hunger. One document prepared for the session looks specifically at the activities of the multilateral institutions since the 1974 conference, in terms of both resource and programme commitments. This article provides a summary of that WFC document.     

After the famine: food aid policy and management issues in sub-Saharan Africa

The large amount of food aid that was required to meet Africa's emergency food situation resulted in the postponement of some fundamental decisions that were being taken about food aid use in sub-Saharan Africa. Now the donor community and recipient governments are again giving priority to integrating food aid with other available resources in order to meet longer-term food policy and wider development objectives. This paper looks at some of the policy and management issues which need to be addressed if the effectiveness of food aid assistance is to be improved in the current African context. Shortages of locally qualified personnel to administer project food aid have proven to be a major bottleneck in most sub-Saharan countries. Most sub-Saharan states receive food aid from a variety of sources: multilateral, bilateral and a few private-voluntary organizations. As a result, countervailing priorities are set by the donors themselves and give rise to conflicts. The recent drought and famine conditions have compounded an image problem in which food aid is narrowly identified by recipient governments as a project resource to be used primarily for nutrition interventions and for the rural sector. The image problem often limits project selection and overlooks innovative uses of food aid. Many sub-Saharan countries are starting to acquire considerable amounts of counterpart funds from program food aid. However, their use is not coherently integrated with the total aid flow. Multi-year programming has emerged as a management issue which has unnecessarily divided the food aid donor community. The fundamental issue is flexibility in programming, not multi-year programming. The major policy objective now facing the food aid donor community and recipient countries is how to lower emergency allocations while simultaneously increasing project and program aid. Most nonfood-aid donor agencies and their constituent bodies do not treat food aid as a valid economic resource, thereby undermining its effectiveness. The eventual success of food aid use in Africa may be a function of the recipient governments and other major donor and financial organizations.     

Are your employees minding their behavior?

Self-managed, "tailored" behavioral change programs cross both wellness and disease management issues and can impact the bottom line on health care costs of both employer and employee. For example, a back pain program can help change employee behavior to prevent the incidence and upflow of a condition to more severe and debilitating situations.