Snel terug naar school : begeleiding jongeren met onbegrepen lichamelijke klachten moet beter

0-19, PZ

Are Revisions to USDA Crop Production Forecasts Smoothed?

This article uses Nordhaus' framework to determine the efficiency of the revision process for USDA corn and soybean production forecasts over the 1970/1971 through 2004/2005 marketing years. Positive autocorrelation and consistency of directional changes in forecast revisions suggest these forecasts are “smoothed.” Evidence is provided that the loss in forecast accuracy due to smoothing is statistically and economically significant in several cases. A conservative bias in farm operators' assessments of yield potential and in the procedure for translating enumerator's information about plant fruit counts into objective yield estimates are identified as plausible sources of smoothing. Copyright 2006, Oxford University Press.

Aggregation of Price Risk over Commodities: An Economic Index Number Approach

This article extends the economic theory of index numbers to the aggregation of price risk over commodities in production. Superlative indexes of aggregate price risk are related to Tornqvist and Fisher—type output quantity indexes. An application to major crops in Manitoba illustrates the empirical importance of the analysis. Copyright 2007, Oxford University Press.