Abdelmoneim H. Elnagheeb

WILLINGNESS TO PAY FOR IMPROVEMENTS IN DRINKING WATER QUALITY

In this paper, data from a 1991 survey of Georgia residents were used to study peoples willingness to pay (WTP) for improvements in drinking water quality and peoples perceptions of potential groundwater contamination. Results showed that 27% of the respondents served by public water supplies rated drinking water quality as poor, and 23% were uncertain about their drinking water quality. The contingent valuation method was used to estimate WTP using a checklist format. The median estimated WTP was

Extensification of agriculture and deforestation: empirical evidence from Sudan

5.49 per month above their current water bills for people on public systems and

Modeling Perennial Crop Supply: An Illustration from the Pecan Industry

7.38 for those using private wells, after rejecting outliers and using the maximum likelihood method. The aggregate WTP for all of Georgia was estimated to be about

Risk perception and new food production technologies

111.5 million per year for public water users and

Willingness to pay for pST-treated pork

42.3 million per year for private well owners. This aggregate WTP can serve as an estimate of benefits to consumers from improvements in drinking water quality statewide.

Rainfed mechanized farming and deforestation in central Sudan

Extensification of agriculture is one of the major factors contributing to the destruction of forests in Africa. In Sudan, such horizontal expansion comes at the expense of land devoted to trees and other vegetation, thereby inducing conditions that are inimical to sustainable agricultural production. Different factors have contributed to extensification. Although high economic returns from crop (mainly sorghum) production was an important factor encouraging extensification of rainfed mechanized farming, other factors outside agriculture have also contributed to that expansion. This paper uses data from eastern Sudan and an acreage response model, to identify the most important factors influencing acreage expansion. Different measures and forms of risk were used in the acreage response model. The paper shows how policies in the energy sector can indirectly influence acreage expansion in the agricultural sector.

Consequences of Using Different Question Formats in Contingent Valuation: A Monte Carlo Study

Two methodological approaches were applied to estimating the number of non-bearing trees in the absence of such date using data for the Southern USA pecan industry. The first approach distinguished between bearing and non-bearing phases of a tree life and directly estimated the number of non-bearing trees. The second focused on indirect estimating of the non-bearing tree number from changes in production. This approach relaxed the assumption of maintaining maximum yields for infinite period as used in earlier studies. Empirical applications used two data sets from the pecan industry. The comparison of empirical results suggested that the first method was more accurate than the alternative approach in predicting the number of newly planted trees over an extended period of time. Additional data collection will allow for further application of available methodology to the pecan industry.

PUBLIC PERCEPTIONS OF FOOD SAFETY

In this study, survey data were used to develop a model to measure the relationship between a set of socio-economic characteristics of consumers and their risk perception of feed additives and growth hormones use in livestock production. Perceptions were measured indirectly by constructs based on responses to multiple questions. Factor analysis was used to identify the perception measures. Next, two econometric approaches were applied to estimate the relationships between the explanatory variables and risk perceptions. Estimation results gave both the direct and total effects of each explanatory variable on the three constructs: risk perception due to the use of feed additives and antibiotics in livestock and poultry, risk perception due to the use of bioengineering in food production or its specific example - the porcine somatotropin (pST) - the pig growth hormone, and support of pST use in pig production.

Comparing Three Approaches That Generate Bids for the Referendum Contingent Valuation Method

The progress in porcine somatotropin (pST) application justified an assessment of consumer acceptance of pST-treated pork. A survey of the Atlanta metropolitan area, USA, collected information about consumer attitudes toward lean pork produced with biotechnologically developed pST. A qualitative dependent variable model was used to identify socioeconomic consumer characteristics influencing the willingness to pay for lean pork. The model was modified to account for the selectivity bias of the sample data. Results indicate that frequent pork consumers were willing to pay more for lean pork produced using pST in contrast to respondents who frequently ate beef, were older, and had relatively high income. Probabilities associated with the willingness to pay a specific premium were calculated. In general, the average respondent was willing to pay an additional 18¢ per kg of lean pork produced using pST.

DIFFERENCES IN CONTINGENT VALUATION ESTIMATES FROM REFERENDUM AND CHECKLIST QUESTIONS

Sudan is threatened by a serious deforestation problem. Total forested area decreased by about 20 percent over the last two decades, largely as a result of the expansion of rainfed mechanized farming (RMF). To safeguard against the problems of deforestation, the governments Mechanized Farming Corporation requires each farmer to leave at least ten percent of the total farm area under shelterbelts. Few farmers pay attention to this clause. This paper addresses the problem of RMF expansion and analyzes the effects of different factors on the preservation of shelterbelts. Results indicate that the following factors influence the decision to preserve shelterbelts: farmers belief in the value of shelterbelts, the production of gum arabic, farm size, farmers wealth, years a farm has been cultivated, and type of farm.