Panel and Pseudo-Panel Estimation of Cross-Sectional and Time Series Elasticities of Food Consumption
比较了截面、伪面板和真实面板数据估计食品消费收入弹性的偏差，发现未观测异质性导致在家食品弹性低估、在外食品弹性高估，而差分估计量结合工具变量可减少测量误差影响。
The problem addressed in this article is the bias to income and expenditure elasticities estimated on pseudo-panel data caused by measurement error and unobserved heterogeneity. We gauge empirically these biases by comparing cross-sectional, pseudo-panel and true panel data from both Polish and American expenditure surveys. Our results suggest that unobserved heterogeneity imparts a downward bias to cross-section estimates of income elasticities of at-home food expenditures and an upward bias to estimates of income elasticities of away-from-home food expenditures. "Within" and first-difference estimators suffer less bias, but only if the effects of measurement error are accounted for with instrumental variables.