Reduced Form Auctions Revisited

This note uses the Theorem of the Alternative to prove new results on the implementability of general, asymmetric auctions, and to provide simpler proofs of known results for symmetric auctions. The tradeoff is that type spaces are taken to be finite.     

A child health production function estimated from longitudinal data. Cebu Study Team

Collaborating researchers used a multi equation model to analyze 3080 mother-infant pairs living on the island of Cebu in the central Philippines and to estimate a child health production function. The econometric methods used eliminated obstacles such as heterogeneity and endogeneity of significant explanatory factors. They also maximized the longitudinal quality of the data. The results showed that morbidity in 1 period reduced infant weight in following periods. For example, diarrhea and febrile respiratory infection reduced growth in the time period following the illnesses. Further effects of some contributing factors were great near birth not diminished with age. For example, breast feeding promoted growth and protected against infection, especially diarrhea and febrile respiratory infection, more substantially near birth than it did later. Further, in urban areas, preventive health care positively affected growth independently of its indirect influence on reducing respiratory infection. Yet it had little effect on diarrhea. Diarrhea had a strong adverse effect on growth. Exposure of the infant to enteric pathogens had the greatest influence on production of diarrhea. In urban areas, exposure included water supply contamination, exposure to feces, a more pathogenic diet, and community crowding. In rural areas, however, exposure included community crowding and increased rainfall which presumably washed feces into the water supply. Household crowding in both urban and rural areas and irritation from smoke in urban areas only tended to bring about febrile respiratory infection.     

Developing holistic leaders: Four domains for leadership development and practice

Leadership development and practice have traditionally been quite narrow, with a decided focus on the analytical realm of leadership. However, the contemporary climate of corporate scandal and resultant loss of societal confidence, coupled with the evolving demands, needs, and expectations of employees, point to the potential need for a more holistic approach to leadership. Thus, this article proposes how management education and leadership development programs can develop holistic leaders that are adept at operating in the analytical, conceptual, emotional, and spiritual domains of leadership practice. An integrated model for holistic leadership development and practice that addresses all four of these domains is proposed, and grounded in both established and emerging leadership development theory. Additionally, a leadership development classification scheme is proposed based on classroom, job, and organizational contexts.     

The demographic impact of AIDS in sub-Saharan Africa: short- and long-term projections

"This paper describes the methodology used to incorporate AIDS mortality in recently revised World Bank population projections....The paper first reviews different approaches for projecting AIDS and its demographic consequences. This is followed by a summary of an epidemiological model that simulates the spread of HIV used in this analysis, and a demographic model that translates mortality from AIDS into population outcomes. These models are then used in a set of simulations, from which the effect of current HIV prevalence on projected future mortality is extracted. Finally, the extracted equations linking current HIV prevalence with future mortality indicators are applied to sub-Saharan countries with a measurable level of current HIV prevalence."     

Common factors can always be found but can they also be rejected?

Factor models are often used to reduce the complexity of data. It is simple to find common factors and to interpret them. However, it is doubtful whether factor models are always appropriate. Especially when the common factor is considered to be an attitude, it must be stable through time and explain a considerable part of the variances. A procedure is suggested to test the usefulness of a common factor. In an experimental pilot study in which an attitude towards immigrant workers was investigated, the instability and superfluousness of a common factor is shown. An alternative model is presented which suggests that changing opinions can be explained by specific variables. Finally it is shown that a more stable common factor is found if a so-called MIMIC-design is used.