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Iowa State Land Value Survey. Started in 1942; time series available since 1950 Mailing list is updated through County Extension Offices Approximately 1100 surveys mailed each year Approximately 600 useable surveys per year; at least 3 per county.
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Iowa State Land Value Survey • Started in 1942; time series available since 1950 • Mailing list is updated through County Extension Offices • Approximately 1100 surveys mailed each year • Approximately 600 useable surveys per year; at least 3 per county
Iowa State University Land Value SurveyCalculations • Step 1: By county, calculate the average value for high, medium and low quality land reported in the survey • Step 2: Calculate weighted average county values (weights from 1977 survey of H,M,L quality land in each county)
ISU Land Value Survey Calculation (cont) • Step 3: Adjust weighted value by the relation of the county value to the average value in the Walker district from the last Census of Agriculture Note: Walker districts are counties with similar CSR ratings. • Step 4; Adjust the adjusted weighted county values by the number of common border miles with adjoining counties in a different Walker district
Iowa State Land Value Survey • Purpose of the adjustments is to account for changes in surrounding counties • Adjustments allow estimates to be based on more than just the respondents for the county • Adjustments have been done consistently for the past few decades
Possible Changes to Calculating ISU Land Values • Use simple weighting scheme with weights gained from the 1977 survey • Use weighting system with weights determined by CSR and land in each county • Use State wide values to determine the range for high, medium and low based on thirds; 0 – 40 CSR is low; 41 – 68 CSR is medium; and > 68 is high
Issues with ISU Land Value Survey • Using alternative weighting system is easier • CSR weighting system allows comparison based on yields • Problem with changing data set series • How far back we can reconstruct is unknown • Reliability of the data set with just simple weights
Iowa State Land Value SurveyRecommendations • Leave the estimation procedure as it is • Increase the sample sizes by trying to expand the survey list • Evaluate possible fifth step in the estimation procedure to help further account for relative changes in the county values and the Walker districts