Efficient specific investments, incomplete contracts, and the role of market alternatives

Investment

Plasma zinc concentrations are depressed during the acute phase response in children with falciparum malaria

Plasma concentrations of some micronutrients are altered in the setting of acute infectious or inflammatory stress. Previous studies have provided conflicting evidence concerning the extent and direction of changes in plasma zinc concentrations during the acute phase response. We carried out an observational cohort study in 689 children enrolled in a randomized trial of zinc supplementation during acute falciparum malaria in order to evaluate the relation between plasma zinc concentration and the acute phase response. Plasma zinc was measured by atomic absorption spectrophotometry. On admission, 70% of all subjects had low plasma zinc (\u3c9.2 μmol/L). Multivariate analysis of predictors of admission plasma zinc showed that admission C-reactive protein (CRP), parasite density, and study site were the most important predictors. Predictors of changes in plasma zinc from admission to 72 h included baseline CRP, change in CRP, treatment group, study site, and baseline zinc concentration. In children with acute malaria infection, baseline plasma zinc concentrations were very low and were inversely correlated with CRP (r = -0.24, P \u3c 0.0001) and the degree of parasitemia (r = -0.19, P \u3c 0.0001). Even when CRP and time were taken into account, zinc supplementation increased plasma zinc concentration from admission to 72 h. When available, plasma zinc concentrations should be interpreted with concurrent measures of the acute phase response such as CRP. In children whose age, diet, and/or nutritional status place them at risk of zinc deficiency, those with low plasma zinc levels should be supplemented with oral zinc and followed for clinical and/or biochemical response. © 2005 American Society for Nutritional Sciences

Age, temperature, and parasitaemia predict chloroquine treatment failure and anaemia in children with uncomplicated Plasmodium falciparum malaria

The prevalence of chloroquine-resistant Plasmodium falciparum malaria has been increasing in sub-Saharan Africa and parts of South America over the last 2 decades, and has been associated with increased anaemia-associated morbidity and higher mortality rates. Prospectively collected clinical and parasitological data from a multicentre study of 788 children aged 6-59 months with uncomplicated P. falciparum malaria were analysed in order to identify risk factors for chloroquine treatment failure and to assess its impact on anaemia after therapy. The proportion of chloroquine treatment failures (combined early and late treatment failures) was higher in the central-eastern African countries (Tanzania, 53%; Uganda, 80%; Zambia, 57%) and Ecuador (54%) than in Ghana (36%). Using logistic regression, predictors of early treatment failure included younger age, higher baseline temperature, and greater levels of parasitaemia. We conclude that younger age, higher initial temperature, and higher baseline parasitaemia predict early treatment failure and a higher probability of worsening anaemia between admission and days 7 or 14 post-treatment

Motivation and markets

Many workers receive pay based on subjectively assessed performance, yet the shirking model of efficiency wages excludes it. This paper incorporates such pay, with the following results. Performance pay is more efficient than efficiency wages when the costs of having a job vacant are low and qualified workers in short supply. More capital-intensive industries pay more than less capital-intensive industries, as observed in studies of interindustry wages differentials. Sustaining an efficient outcome requires a social convention similar to the notion of a fair wage. The model also makes predictions about the relationship between turnover, wages, growth and unemployment

Turnover costs, efficiency wages and cycles

This paper studies the implications of our recent work on two labor market imperfections for the cyclical properties of wages and employment. One of these imperfections is turnover costs. We explore the implications of the interaction of turnover costs with investment decisions for the form of wage contracts and hence for the cyclical properties of wages. The other imperfection is the difficulty of verifying employee performance. We consider the implications of this for the payment of efficiency wages and the consequence for the cyclical properties of wages and emloyment

Contract bargaining with symmetric information

This paper reviews a recent literature that extends the Rubinstein/Stahl bargaining model to the case of contract bargaining. Theoretical issues, such as the appropriate game form, existence, and uniqueness of equilibria, are discussed. The paper finishes with a brief overview of some applications of the framework