Quadratic Engel Curves with Measurement Error: Evidence from a Budget Survey*
利用1994年埃塞俄比亚城市家庭调查数据，采用修正相关测量误差的估计方法，发现首都食品支出份额与总支出之间存在稳健的二次关系，并指出未修正测量误差的估计存在显著偏误。
Abstract This paper examines the importance of accounting for measurement error in total expenditure in the estimation of Engel curves, based on the 1994 Ethiopian Urban Household Survey. Using Lewbel's [ Review of Economics and Statistics (1996 ), Vol. 78, pp. 718–725] estimator for demand models with correlated measurement errors in the dependent and independent variables, we find robust evidence of a quadratic relationship between food share and total expenditure in the capital city, and significant biases in various estimators that do not correct for correlated measurement errors.