Working Paper No. 494

On Omitted Variable Bias and Measurement Error in Returns to Schooling Estimates

Published: February, 1998Pages: 19Keywords: Missing data, Proxy variables, Measurement error, Partial correlations, SimulationsJEL-codes: C13, C20, J31

On Omitted Variable Bias and Measurement Error in Returns to Schooling Estimates Erik Mellander

Lam and Schoeni (1993) consider an equation where earnings are explained by schooling and ability. They assume that ability data are lacking and that schooling is measured with error. The estimate obtained by regressing earnings on schooling thus contains omitted variable bias (OVB), which is positive, and measurement error bias (MEB), which is negative. Adding a family background variable to proxy for ability is claimed to: i) decrease the OVB towards, but not below, zero and ii) make the MEB even more negative. This note claims that while ii) is true, even in the context of multiple family background variables, i) is in general incorrect. The OVB may increase in magnitude and/or change sign. Conditions are provided under which i) holds. A simulation procedure is suggested that will yield consistent estimates of the total bias and its components, conditional upon values on the true return and the measurement error variance.

Sick of Inequality?

An Introduction to the Relationship between Inequality and Health

Sick of Inequality.jpg

In this book Andreas Bergh, Therese Nilsson, IFN and Lund University, and Daniel Waldenström, IFN and Paris School of Economics, France, review the latest research on the relationship between inequality and health. What does inequality mean for our health? Does increasing income inequality affect outcomes such as obesity, life expectancy and subjective well-being?


Seminars organized by IFN


To present ongoing research informal brown-bag seminars are held on Mondays at 11:30 am. This is an opportunity for IFN researchers to test ideas and results.

Academically oriented seminars are most of the time held on Wednesdays at 10 am. At these events researchers from IFN and other institutions present their research.

In addition, IFN organizes seminars open to the public. Topics for these are derived from the IFN research.

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