Degrees of Processing and Changes in the Cyclical Behavior of Prices in the United States, 1869-1990
指出二战前后价格指数对加工程度不同的产品权重不同，导致对总价格水平周期行为变化的度量有偏，需区分产品本身价格行为的变化与构成变化的影响。
Price indices for periods before the Second World War place more weight on less-processed products than do their postwar counterparts to an extent that exaggerates the change over time in the composition of aggregate output. Prices of less-processed products are especially procyclical in levels and inflation rates. Thus, comparisons between historical and postwar series can give biased measures of changes in the cyclical behavior of the aggregate price level. Also, changes in the behavior of the aggregate price level must be distinguished from changes in the behavior of prices of given products, subject to a given degree of processing.