Analyzing Nonresponse Bias in PPI Data

Boriana Chopova, Teresa E. Hesley, Greg Kelly, Soon Paik, Andy Sadler, and Dave Slack


The Producer Price Index (PPI) program conducted a study to determine if nonresponse bias exists in PPI data. The study investigated nonresponse at unit initiation (when units are asked to participate in PPI samples) and during the unit/item repricing period (when units provide prices for the items they've agreed to reprice at initiation). The study consisted of three stages: In the first stage a contingency table analysis and regression models were used to analyze the relationship between response and several frame variables. In the second stage a regression model was used to analyze the relationship between item short term relatives and the variables which were associated with response from the first stage. The third stage tested the impact of sample adjusted weights on PPI indexes. This paper reports the results of this study.