This paper illustrates two techniques for calculating the statistical significance of the marginal effects derived from Heckman’s sample selection model,an increasingly common econometric specification in political science. The discussion draws on an analysis by Sweeney (2003) of the incidence...

Using a panel of household travel diary data collected in Germany between 1997 and 2005, this study assesses the effectiveness of fuel efficiency improvements by econometrically estimating the rebound effect, describing the extent to which higher efficiency causes additional travel.Following a...

This study examines the determinants of urbanized area across a 10,000-mile square swath in central North Carolina, an area undergoing extensive conversion of forest and agricultural land.We model the temporal and spatial dimensions of these landscape changes using a database that links five...