Modelling the Crop Variety Demand of Semi‐Subsistence Households: Bananas in Uganda

We propose an approach to model the derived demand for crop varieties among semi‐subsistence farmers in a developing economy, and apply it to smallholder banana producers in Uganda. We model variety planting decisions as being composed of an extensive margin decision to grow a subset of locally available varieties (variety choice); and an intensive margin decision about the scale or extent of variety cultivation per farm (variety demand). We estimate variety demand equations using a more complete representation of the choice set upon which observed planting decisions are made. Computed elasticities of variety demand with respect to variety attributes indicate that the relative importance of consumption and production attributes varies by location and proximity to markets, from which we draw implications for the social and economic impact of crop improvement. The approach that we propose has broad appeal for analysing adoption decisions for modern or traditional varieties of both major and minor crops in developing countries.     

Global analysis and economics IV : Finiteness and stability of equilibria with general consumption sets and production

Among other things a global version of the fundamental theorem of welfare economics is proved. One starts with a pure exchange economy with fixed total resources where hypotheses of differentiability, convexity, and monotonicity are made on the utility functions. Let be the set of price equilibria where the initial allocation coincides with the final one. Then the map which assigns to such a price equilibrium, the corresponding allocation is a diffeomorphism (a complete correspondence) between and the set of Pareto Optima.     

Input subsidies and crop diversity on family farms in Burkina Faso

Since their independence, many countries in sub-Saharan Africa have used input subsidies to increase agricultural productivity and improve food security. We analyse the effects of both a fertiliser and a seed subsidy on farming households' land allocation among crops and crop diversity in Burkina Faso. Although previous studies investigated either the impact of a fertiliser or a seed subsidy on targeted crops, few examined the effects of both subsidies combined. Applying a correlated random-effects model with a control function approach to nationally representative, 2-year panel data collected from farming households, we find that those with access to the fertiliser subsidy allocate more land to the crops it targets (rice, maize and cotton) than non-targeted crops. Focusing on a minor crop with key agronomic and nutritional attributes, we conclude that land allocation to cowpea as the primary crop and intercrop declined with the fertiliser subsidy. The fertiliser subsidy also negatively affects crop diversity. However, we find that the cowpea seed subsidy offsets the bias of fertiliser subsidy toward fertiliser-targeted crops and enhances diversity.     

Farmer management of production risk on degraded lands: the role of wheat variety diversity in the Tigray region, Ethiopia

This article investigates the effects of wheat genetic diversity and land degradation on risk and agricultural productivity in less favored production environments of a developing agricultural economy. Drawing production data from a household survey conducted in the highlands of Ethiopia, we estimate a stochastic production function to evaluate the effects of variety richness, land degradation, and their interaction on the mean and the variance of wheat yield. Ethiopia is a center of diversity for durum wheat and farmers manage complex variety mixtures on multiple plots. Econometric evidence shows that variety richness increases farm productivity. Variety richness also reduces yield variability but only for high levels of genetic diversity. Simulations with estimated parameters illustrate how planting more diverse durum wheat varieties on multiple plots contribute to improving farmer's welfare.     

The economic impact of productivity maintenance research: breeding for leaf rust resistance in modern wheat⋆

This paper reports the results of a study undertaken to estimate the economic impact in developing countries of efforts by the International Maize and Wheat Improvement Center (CIMMYT) to breed leaf rust resistant spring bread wheat varieties since 1973. The challenge in estimating these benefits lies in the pathogen's ability to mutate to new races, which may infect previously resistant varieties. Genetic resistance, rather than fungicide application, is the principal means of controlling leaf rust in developing countries. Whereas productivity enhancement is often estimated in terms of yield gains and increased supply, productivity maintenance is measured in terms of the yield losses avoided by the research investment. The internal rate of return on CIMMYT's research investment was estimated at 41%. When discounted by 5%, the net present value was US$ 5.36 billion in 1990 dollars, and the benefit‐cost ratio was 27:l. These findings emphasise the economic importance of maintenance research in crop breeding programs.     

Localized sentiment trading in heterogeneous labor markets: evidence from free agent signings

We show that free agent signings in U.S. professional sports are associated with localized sentiment trading effects. Responses are influenced by player performance, labor contract and sport structure characteristics unique to each league. Football signings lack guarantees and are noisy signals while the most informative baseball signings reflect player performance. Sentiment effects of basketball signings are mixed. Investors respond positively to contract extension announcements, but negatively to new contract negotiations, with either the current team or a different franchise. Exceptions are for free agents with high performance rankings or who are perceived to improve the odds of winning a championship. We also provide some evidence that sentiment trading is driven primarily by retail investors.