A double-differences approach to inference in regression discontinuity designs with a discrete running variable

Georg Graetz () and Mattias Nordin ()
Additional contact information
Georg Graetz: Department of Economics, Uppsala University
Mattias Nordin: Department of Statistics, Uppsala University

No 2026:19, Working Paper Series from IFAU - Institute for Evaluation of Labour Market and Education Policy

Abstract: We present a new approach to nonparametric inference in regression discontinuity designs where the running variable is discrete and may have few support points. The approach is based on an intuitive and comparatively weak identification assumption: In the absence of treatment, the difference in population mean outcomes at the cutoff is not the largest nor the smallest among differences at any two adjacent support points. Test statistic and confidence interval are constructed from a set of t-statistics based on double differences of the outcome variable, eliminating the need to estimate a conditional expectation function. Simulation evidence suggests that statistical power compares favorably to existing methods. We illustrate our approach by revisiting two studies from the economics of education literature.

Keywords: Regression discontinuity design; causal inference; policy evaluation; economics of education (search for similar items in EconPapers)
JEL-codes: C12 C13 C14 I21 (search for similar items in EconPapers)
Pages: 48 pages
Date: 2026-09-25
New Economics Papers: this item is included in nep-ecm
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.ifau.se/globalassets/pdf/se/2026/wp-20 ... running-variable.pdf Full text (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:hhs:ifauwp:2026_019

Access Statistics for this paper

More papers in Working Paper Series from IFAU - Institute for Evaluation of Labour Market and Education Policy IFAU, P O Box 513, SE-751 20 Uppsala, Sweden. Contact information at EDIRC.
Bibliographic data for series maintained by Malin Lindkvist ().