James O. Bukenya

Crime Trend and Socio‐economic Interactions: A County‐level Analysis

This article contributes to the identification and interpretation of socio‐economic and demographic correlates of crime in Alabama using county‐level data. The results of the estimated regression model are generally consistent with previous studies in suggesting that several socio‐economic and demographic variables, such as education and unemployment, influence crime trend. Conversely, the results also confirm previous conclusions that law enforcement, as measured by county‐level police expenditures, has no effect on crime rates.

EFFICIENCY OF RESOURCE USE AMONG POND FISH FARMERS IN CENTRAL UGANDA: A STOCHASTIC FRONTIER PRODUCTION FUNCTION APPROACH

This article presents the use of a stochastic frontier production function to examine the efficiency of resource utilization in pond fish farming in Uganda. The study draws on data from a field survey administered to 200 small-scale fish farmers in three major fish farming districts in Central Uganda: Mukono, Mpigi and Wakiso. The districts were part of a large aquaculture development project funded by the United States Agency for International Development-Aquaculture and Fisheries Collaborative Research Support Program. Productive efficiency was analyzed using stochastic frontier analysis with a translog production function while assuming a truncated-normal distribution for the inefficiency term. The output variable was total quantity of fish produced, while input variables were quantity or value of inputs used in the production process, namely labor, pond size, stocking density, capital and feeds. The estimated index of resource-use efficiency revealed that small-scale farmers were inefficient in resource allocation by over-utilizing labor with an estimated allocative efficiency index of −0.94 and grossly under-utilized pond size, feeds and fingerlings with allocative efficient indices of 1.15, 1.64, 3.71, respectively. The results suggest that there is considerable scope to expand output and also productivity by increasing production efficiency at the relatively inefficient farms and sustaining the efficiency of those operating at or closer to the frontier.

Impact of low carbohydrate information on vegetable demands in the United States

An almost ideal demand system was estimated to examine the impacts of low carbohydrate information on the demand of vegetables in the United States. Analysis was extended to examine the performance of alternative carbohydrate information indices. Results show significant impacts of low carbohydrate information across all included vegetables. Results indicated the superiority of the general and weighted carbohydrate information index specifications.

Assessing the impacts of stochastic trend in crop acreage supply response model

This paper demonstrates the need to revisit the way a technical change has been incorporated in a crop acreage supply response model. Three different versions of technological change were introduced and compared: no trend, deterministic trend, and stochastic trend. The results confirm the need to treat a technology variable as a stochastic trend for better results in crop acreage supply response model specifications.

Modelling swine supply response using a structural time series approach

Swine supply response was analyzed using a structural time series model (STSM) with both seasonal and yearly effects introduced stochastically. Swine production is divided into four production phases. Parameters of each phase were then estimated using a structural time series model. Out-of-sample forecasting robustness of the STSM was compared against a commonly used deterministic trend and deterministic seasonally (DTDS) using root mean square error and mean absolute percentage error criteria. The STSM model produced lower RMSE and MPE values than those obtained using a DTDS modeling approach.

Demand Elasticities for East African Fish Exports to the European Union

In this study, the authors estimate demand elasticities for East African fish exports to the European Union. Today, fish is one of the most important renewable resources in East Africa, and ranks as the regions highest nontraditional agricultural export earner. Furthermore, fish represents a vital contribution to the food and nutritional security of millions of people in the region and the sizeable export revenue it generates plays an important role in advancing the regions development strategy of increasing overall foreign exchange earning capability. In this respect, elasticity is one of the basic indicators when discussing policy impacts, but currently there are no elasticity estimates for East Africas fish export demand to guide trade policy formulation. The results for the estimated export demand equation showed evidence of lower price and higher income elasticities, implying that, on one hand, the European Unions demand for East Africa fish is more sensitive to income changes than price changes and, on the other hand, the East African fishery industry can simultaneously reduce the rate of resource use while boosting fishery income through higher prices.

Price Leadership on the World Crude Oil Market

The paper investigates the role of Saudi Arabia in the dynamic behavior of world crude oil prices over recent decades. The analysis tests the hypothesis that Saudi Arabian crude oil prices lead crude oil prices on the world market. If Saudi Arabian crude oil price has led the prices of other countries on the world crude oil market, there would be a long- run equilibrium relationship between each countrys crude oil price and Saudi Arabian price. Comparable geographic data were assembled for six OPEC (Iran, Indonesia, Libya, Nigeria, Saudi Arabia and Venezuela) and six non-OPEC (Canada, China, Mexico, Norway, United Kingdom and United States) countries, covering the period 1970 through 2007. Three widely used econometric techniques (dynamic correlation analysis, cointegration analysis and VAR analysis) are employed. The results support a long-run equilibrium relationship between Saudi Arabian crude oil price and prices in other OPEC and non-OPEC countries.

Avoidance Measures and Household Perceptions of Water Quality in Uganda

ABSTRACT The importance that households place on reducing health risks from drinking water can guide policies intended to enhance safety. Self-reported household water quality opinions and avoidance measures used by households in Kampala, Uganda, to manage health risks were analyzed. The paper is based on survey data collected from four divisions in Kampala district and analyzed using binary logit model. Survey results indicate that the majority of the respondents boil water to manage potential health risks. On the other hand, logit results confirmed the existence of strong relationships between household characteristics, opinions on water quality, and the use of avoidance measures.

Dairy supply response under stochastic trend and seasonality

Developing a dairy supply model assuming deterministic trend and seasonality a priori could lead to model misspecification. A structural time series methodology was used to examine the role of stochastic trend and seasonality in a dairy supply response model using quarterly time series data. Four versions of a time-linked model of dairy supply response were compared. A dairy supply model with stochastic seasonality and deterministic trend performed the best, as evidenced by diagnostic tests, goodness-of-fit measures, and forecasting accuracy. Our analysis suggested against the classic approach of incorporating the deterministic seasonality component in dairy supply models.

Price Transmission and Threshold Behavior in the African Catfish Supply Chain in Uganda

Abstract The issue of price linkage in the catfish supply chain in Uganda is important because catfish has become an important traded species with exports to regional markets rising even faster than production, yet limited research has been undertaken to understand the linkages and the non-linearity in the price transmission mechanism. This paper explores the issue using monthly price data from January 2006 to August 2013, and applies threshold autoregressive approaches to test for the existence of a long-run relationship and price asymmetry. The results show that prices in the catfish value chain are tied together by a long-run relationship. It is also revealed that ex-vessel and wholesale price adjustments to retail price changes are symmetric while ex-vessel price adjustments to wholesale price changes are shown to be asymmetric. The direction of causal relationships was observed from the retail to the wholesale and ex-vessel markets, indicating that retailers are the price leaders in the Uganda catfish supply chain.