Learning-by-doing and the sources of productivity growth: A dynamic model with application to U.S. agriculture

The significance of learning to productivity growth is formulated within a dynamic adjustment-cost framework. Explicitly treating the acquisition of knowledge as a firm-specific capital good entering the production function along with other conventional inputs, the dynamic optimization model integrates the learning-by-doing hypothesis with technical change, scale, and disequilibrium input use effects in the aggregate productivity analysis. The theoretical framework is applied to examining the dynamic components accounting for the growth of U.S. production agriculture over the 1950–82 period. The results imply a less important role for technical change and assign a substantial role to the previously unmeasured contribution of learning-by-doing to the growth of aggregate agriculture industry.The editor for this paper was Melvyn Fuss.     

The generality/specificity issue in consumer innovativeness research

The purpose of the present study was to explore the role of personality in shaping consumer innovativeness by testing a model of the hierarchical relationships between a global (broad or abstract) personality trait, its domain-specific manifestation in a consumer context, and overt consumer behavior. A survey of 465 adult consumers measured global innovativeness, domain-specific innovativeness for two product categories (clothing and electronics) and self-reported purchase of new clothing and electronic items. Three hypotheses were tested. First, global innovativeness is more highly correlated with domain-specific innovativeness than it is with the purchase of new items. Second, domain-specific innovativeness is more highly correlated with the purchase of new items than is global innovativeness. Finally, the association between global innovativeness and new product purchase is mediated by domain-specific innovativeness. All three hypotheses were supported for both product categories.     

The effects of group decision-making process and problem-situation complexity on implementation attempts

The effects of group problem-solving method and problem-situation complexity on attempts at implementing group solutions were investigated in a laboratory-field setting. Group members were supervisory nurses from various organizations, who were randomly assigned to three groups in a balanced research design which included three group decision-making processes and three levels of problem-situation complexity in implementation. The dependent variable was the number of attempts at implementing group-derived solutions in home organizations. The results showed that structure in group decision-making processes led to increased rates of implementation attempts at all levels of problem-situation complexity. There was a significant complexity-by-process interaction effect among the decision-making processes, which supports the conclusion that the type of group decision-making process and the problem-situation complexity should be considered in order to optimize the number of implementation attempts.g     

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.     

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."