Running and Jumping Variables in RD Designs: Evidence Based on Race, Socioeconomic Status, and Birth Weights

34 Pages Posted: 16 Aug 2010

See all articles by Alan I. Barreca

Alan I. Barreca

UCLA Institute of the Environment and Sustainability; National Bureau of Economic Research (NBER); IZA Institute of Labor Economics

Melanie Guldi

University of Central Florida - College of Business Administration - Department of Economics; Mount Holyoke College - Department of Economics

Jason M. Lindo

Texas A&M University; National Bureau of Economic Research (NBER); IZA Institute of Labor Economics

Glen R. Waddell

University of Oregon - Department of Economics; Institute for the Study of Labor (IZA)

Abstract

Throughout the years spanned by the U.S. Vital Statistics Linked Birth and Infant Death Data (1983-2002), birth weights are measured most precisely for children of white and highly educated mothers. As a result, less healthy children, who are more likely to be of low socioeconomic status, are disproportionately represented at multiples of round numbers. This has crucial implications for any study using a regression discontinuity design (RDD) in which birth weights are used as the running variable. For example, estimates will be biased in a manner that leads one to conclude that it is good to be strictly to the left of any 100-gram cutoff. As such, prior estimates of the effects of very low birth weight classification (Almond, Doyle, Kowalski, and Williams 2010) have been overstated and appear to be zero. This analysis highlights a more general problem that can afflict regression discontinuity designs. In cases where attributes related to the outcomes of interest predict heaping in the running variable, estimated effects are likely to be biased. We discuss approaches to diagnosing and correcting for this type of problem.

Keywords: regression discontinuity, donut RD, birth weight, infant mortality

JEL Classification: C21, C14, I12

Suggested Citation

Barreca, Alan I. and Guldi, Melanie and Lindo, Jason M. and Waddell, Glen R., Running and Jumping Variables in RD Designs: Evidence Based on Race, Socioeconomic Status, and Birth Weights. IZA Discussion Paper No. 5106, Available at SSRN: https://ssrn.com/abstract=1659085

Alan I. Barreca (Contact Author)

UCLA Institute of the Environment and Sustainability ( email )

Los Angeles, CA
United States

National Bureau of Economic Research (NBER) ( email )

1050 Massachusetts Avenue
Cambridge, MA 02138
United States

IZA Institute of Labor Economics ( email )

P.O. Box 7240
Bonn, D-53072
Germany

Melanie Guldi

University of Central Florida - College of Business Administration - Department of Economics ( email )

Orlando, FL 32816-1400
United States

Mount Holyoke College - Department of Economics ( email )

South Hadley, MA 01075
United States

Jason M. Lindo

Texas A&M University ( email )

Langford Building A
798 Ross St.
College Station, TX 77843-3137
United States

National Bureau of Economic Research (NBER) ( email )

1050 Massachusetts Avenue
Cambridge, MA 02138
United States

IZA Institute of Labor Economics ( email )

P.O. Box 7240
Bonn, D-53072
Germany

Glen R. Waddell

University of Oregon - Department of Economics ( email )

Eugene, OR 97403
United States
541-346-1259 (Phone)
541-346-1243 (Fax)

Institute for the Study of Labor (IZA) ( email )

P.O. Box 7240
Bonn, D-53072
Germany

Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Downloads
57
Abstract Views
622
rank
432,792
PlumX Metrics