In this paper, data from a 1991 survey of Georgia residents were used to study people's willingness to pay (WTP) for improvements in drinking water quality and people's 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 $5.49 per month above their current water bills for people on public systems and $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 $I 11.5 million per year for public water users and $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. INTRODUCTION Agricultural activity can have adverse effects on the environment, including surface and groundwater quality, air quality, wetlands, and human health as a result of pesticide exposure and pesticide residue on food [U.S. Environmental Protection Agency (EPA), 1987]. Over the past 20 years, point source pollution in surface water has been extensively regulated, resulting in a 95% reduction in pollutant loadings [EPA, 1986]. Consequently, nonpoint source pollution, the type caused primarily by agriculture, is now responsible for the large majority of remaining water quality problems. In 1986, nonpoint source pollution accounted for 76% of the remaining loadings in all U.S. lakes, 65% in the nation's rivers and streams, and 45% in the country's estuaries [EPA, 1986]. According to the U.S. Environmental Protection Agency (EPA), agricultural activities account for 50-70% of the nonpoint source loadings [EPA, 1986]. The damage that sediment, nutrients, and other soil erosion-related pollutants cause in streams, lakes, reservoirs, and estuaries has been estimated between $3 and $13 billion in 1980 [Clark, 1985]. Groundwater is a source of drinking water for almost 50% of the U.S. population and over 90% of rural households [Sarnat et al., !987; Walker and Hoehn, 1990]. Nearly one fourth of the U.S. population relies on groundwater pumped from areas with a significant chemical use [Lee and Nielsen, 1989]. A recent survey by the EPA revealed that more than 50% of the nation's wells contain traces of nitrate [Rahm, 1990]. A recent U.S. EPA [1990] survey, based on data from 1300 wells in all 50 states in 1988-1989, found that !9 million people are exposed to nitrates in wells with 1.5 million facing nitrate concentration above the 10 parts per millionth contamination level. The survey also found that 85 million additional people are exposed to nitrates in their community water systems with three million people facing nitrates over 10 ppm. Exposure to nitrates can have severe health consequences such as methemoglobinemia (blue baby disease) in infants and...

Extensification of agriculture is one of the major factors contributing to the destruction of forcsts in Africa, In Sudan, such horizontal expansion comes at thc expcnse of land devoted to trccs and other vegetation, thcrcby inducing conditions that are inimical to sustainable agricultural production. Different factors have contributcd to cxtcnsification. Although high economie returns from crop (rnainly sorghum) production was an important factor encouraging extensification of rainfed mechanized farming, othcr factors outsidc agriculture have also contrihutcd to that expansion. This paper uses data l'rom eastern Sudan and an acrcage responsc model, to identify the most important factors influencing acrcage expansion. Different measures and forms of risk wcre uscd in the acrcagc rcsponse modcl, The paper shows how policies in the energy sector can indirectly influence ucrcugc expansion in the agricultural sector.

Extensification of agriculture is one of the major factors contributing to the destruction of forcsts in Africa, In Sudan, such horizontal expansion comes at thc expcnse of land devoted to trccs and other vegetation, thcrcby inducing conditions that are inimical to sustainable agricultural production. Different factors have contributcd to cxtcnsification. Although high economie returns from crop (rnainly sorghum) production was an important factor encouraging extensification of rainfed mechanized farming, othcr factors outsidc agriculture have also contrihutcd to that expansion. This paper uses data l'rom eastern Sudan and an acrcage responsc model, to identify the most important factors influencing acrcage expansion. Different measures and forms of risk wcre uscd in the acrcagc rcsponse modcl, The paper shows how policies in the energy sector can indirectly influence ucrcugc expansion in the agricultural sector.

No abstract

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 government's 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: farmer's belief in the value of shelterbelts, the production of gum arabic, farm size, farmer's wealth, years a farm has been cultivated, and type of farm. Copyright Kluwer Academic Publishers 1992Deforestation, rainfed mechanized farming, shelterbelts, Sudan, logit model, probit model, random utility model,

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Two methodological approaches were applied to estimating the number of non-bearing trees in the absence of such data 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 indust~,

Elnaghccb, AH., Florkowski, W.J., Huang, Ci-L, and Halbrcndt, C; 1992. Willingncss to pay for pST-treated pork, Agric. Econ.,.The progrcss in porcine somatotropin (pST) application justilïed an assessment of consumer acccptance of pST-treated pork. A survey of the Atlanta metropolitan arca, USA, collected information about consumer attitudes toward lean pork produced with biotcchnologically developed pST. A qualitative dependent variable modcl was used to identify socioeconomic consumer characteristics influcncing the willingncss to pay for lean pork. The modcl was modified to account for the selectivity bias of the sam pie data.Results indieate that frequent pork consumers were willing to pay more for lean pork produced using pST in contrast to respondents who frequently ale bccf', wcre oldcr, and had relativcly high income.Probabilities associatcd with the willingness 10 paya speeific premium wcre calculated. In general, the average respondcnt was willing to pay an additional IX~per kg of lean pork produced using pST.Studies conccrning health impacts of fatty acid consumption have linked saturated fats to high levels of blood cholesterol and increased risk of heart and heart-related diseases. Red meats, beef, and park, are considcrcd high in saturated fats and cholesterol whcn compared to poultry or fish. The importance of nutrition and health influences food choices (National Research Council, 1988). Many consumers were interested in leaner pork