The Change from Red to White Meat: The Role of Technology

Since 1950, the composition of the U.S. meat diet has shifted markedly from red meats to poultry. For example, from 1970 to 1984, on a percapita basis, beef consumption has declined by 6.4 percent, while chicken and turkey consumptions have increased by 37.9, and 42.5 percent respectively (U.S. Department of Agriculture, 1985). The numerous studies of this phenomenon from the demand side (Chavas, 1983; Braschler, 1983; Nyankori and Miller, 1982; Moschini and Meilke, 1984; Wohlgenant, 1985, Thurman, 1987; Chalfant and Alston, 1988) have failed to achieve a consensus as to whether a change in taste contributed to this shift. One reason for the lack of consensus is that the very large price and quantity changes make it difficult to establish whether consumers are on a new indifference map. But there have been no comparable studies of the nature and causes of the technological change that has made these large consumption and price changes possible. A decrease in the relative price of poultry with respect to red meat is in any case a major explanation of recent shifts in meat consumption patterns. The main reason for such a decrease appears to be a higher rate of technical progress in the poultry industry than in the red meat industry. Substantial productivity gains in both the production and marketing of poultry over the last two decades appears to have been translated into lower retail prices for poultry. Although some productivity gains have taken place in the red meat industry, they have not matched the cost reductions in the poultry industry (Chavas, 1987). Thus, a consumption shift from beef to poultry could possibly be interpreted as a response to changing relative prices, the structural change having occurred in the meat industry. This would imply that, if the beef industry desires to maintain or expand its market, it should seek a decrease in the production and marketing costs of beef.

SIGNIFICANCE AND CONTROL OF FUNGAL DISEASES RELATED TO BIRD ROOSTS

Certain fungi have been found frequently as saprophytes in areas containing large amounts of bird excreta. These fungi have the ability to survive, multiply, and cause disease once they have entered a host. Two of these are Crypto-coccus neoformans and Histoplasma capsulatum. Both may easily become airborne and be disseminated throughout an area by the prevailing winds. C. neo-formans is commonly isolated from the excreta of pigeon habitats, and in turn has been associated with clinical cases of cryptococcosis, while blackbird roosts, harboring H. capsulatum, have been responsible for several outbreaks of histoplasmosis. When either of these fungi have become established in nature, the sites may become foci for infection and epidemics may occur if the sites are disturbed. This has led to investigation of these organisms with respect to: 1) the frequency of isolation of H. capsulatum from the soil beneath blackbird roosts in a histoplasmosis endemic area; 2) the infectivity of undisturbed roosts positive for H. capsulatum; and 3) the effectiveness of chemical decontamination of areas containing C. neoformans or H. capsulatum.

ESSAYS ON INTERNATIONAL RESEARCH AND DEVELOPMENT SPILLOVERS

The dissertation consists of three essays on international research and development spillovers. In the first essay, I investigate the degree to which differences in institutional arrangements among Sub-Saharan African countries determine the extent of benefits they derive from foreign research and development spillovers. In particular, I compare the international research and development spillovers for English common law and French civil law Sub-Saharan African countries. I show that differences in the legal origin of the company law or commercial codes in these countries may reflect the extent of barriers they place in the paths of firms that engage in the investment process. To tests this hypothesis, I constructed foreign R&D spillovers variable using imports as weights and employed the endogenous growth framework to estimate elasticities of productivity with respect to foreign R&D spillovers for a sample of 17 English common law and French Civil law Sub-Saharan African countries over the period 1980-2004. My results find support for the hypothesis. In particular, foreign R&D spillovers were higher in the English common law countries than in the French civil law countries. In the second essay, I examine the question of whether technical cooperation grants and overseas development assistance grants induce R&D knowledge spillovers in Sub-Saharan African countries. I test this hypothesis using data for 11 Sub-Saharan African countries over the period 1980-2004. I constructed foreign R&D spillovers using the technical cooperation grants and overseas development assistance grants as weights and employed the endogenous growth framework to provide quantitative estimates of foreign R&D spillover effects in 11 Sub-Saharan African countries. I find that technical cooperation grants and overseas development assistance grants are major mechanisms through which returns to R&D investments in G7 countries flows to Sub-Saharan African countries. However, their influence has declined over the years. Finally, the third essay tests the hypothesis that the relationship between a country's exporters and their foreign purchasing agents may lead to the exchange of ideas and thereby improve the manufacturing process and productivity in the exporting country. I test this hypothesis using disaggregated export data from OECD countries. The foreign R&D capital stock in this essay was constructed as exports weighted average of domestic R&D capital stock. I find empirical support for the hypothesis. In particular, capital goods exports generate more learning effects and therefore best explain productivity in OECD countries than non-capital goods exports.