Assuming a declining correlation in yields as distance between pairs of orchards increases, yield variability in peach production may be reduced by increasing distances among orchards. As a measure of yield variability that avoids possible bias resulting from orchard-specific effects, a...

Sample nonresponse and selection biases that may occur in survey research such as contingent valuation applications are discussed and tested. Correction mechanisms for these types of biases are demonstrated. Results indicate the importance of testing and correcting for unit and item nonresponse...