Baltimore Ecosystem Study Institute of Ecosystem Studies

2011 BES Annual Meeting Presentation and Poster Abstracts

Identifying the effect of down-zoning in Baltimore County on residential subdivision development in Carroll and Harford Counties
Irwin, Elena
Co-Authors: Charles Towe (Department of Agricultural and Resource Economics, University of Maryland,; Allen Klaiber (Agricultural, Environmental and Development Economics, Ohio State University,; Doug Wrenn (Department of

Abstract: We examine the down-zoning policy in Baltimore County, Maryland that was implemented in rural areas of Baltimore County in 1976 and its potential impact on the location and timing of development in the adjacent counties of Carroll and Howard. Using a unique GIS dataset of residential subdivision development from 1970 to 1981 for this three county area within the Baltimore metropolitan region, we use a reduced form approach that relies on the richness of these data to isolate the spillover effect of the down zoning in Baltimore County on residential development in Carroll and Howard counties. Specifically, propensity score matching techniques are used to identify observationally similar treated and control locations in the adjacent counties to the down-zoned locations within Baltimore County. The rate of development is analyzed for the five-year periods before and after the downzoning policy adopted in 1976. We then use a difference-in-difference type estimator to examine the spillover effect of the Baltimore County down-zoning policy on development in Carroll and Harford counties. Our findings indicate that the down-zoning did lead to new development in these other counties that otherwise would not have occurred, but that the magnitude of this spillover effect was modest.