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

Alan Barreca (), Melanie Guldi, Jason Lindo and Glen Waddell ()

No 5106, IZA Discussion Papers from Institute of Labor Economics (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 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 (search for similar items in EconPapers)
JEL-codes: C14 C21 I12 (search for similar items in EconPapers)
Pages: 34 pages
Date: 2010-08
New Economics Papers: this item is included in nep-ecm and nep-hea
References: Add references at CitEc
Citations: View citations in EconPapers (4)

Downloads: (external link)
https://docs.iza.org/dp5106.pdf (application/pdf)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:iza:izadps:dp5106

Ordering information: This working paper can be ordered from
IZA, Margard Ody, P.O. Box 7240, D-53072 Bonn, Germany

Access Statistics for this paper

More papers in IZA Discussion Papers from Institute of Labor Economics (IZA) IZA, P.O. Box 7240, D-53072 Bonn, Germany. Contact information at EDIRC.
Bibliographic data for series maintained by Holger Hinte ().