This note demonstrates that in applied regression analysis, the variance of a coefficient of interest may decrease from the inclusion of a control variable, contrasting with Clarke's assertion (2005, 2009) that the variance can only increase or stay the same. Practitioners may thus be...

This note attempts to reconcile a range of primary methods for dealing with price asymmetry, such as the approaches proposed by Tweeten and Quance (1969), Wolffram (1971) and Houk(1977). Using Wolffram’s stylized example, we first illustrate that the notion of asymmetry can be captured in a...

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...

The confluence of factors driving urban growth is highly complex, resulting from a combination of ecological and social determinants that co-evolve over time and space. Identifying these factors and quantifying their impact necessitates models that capture both why urbanization happens as well...

Interaction effects capture the impact of one explanatory variable x1 on the marginal effect of another explanatory variable x2. To explore interaction effects, so-called interaction terms x1x2 are typically included in estimation specifications. While in linear models the effect of a marginal...

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...

We specify a system of equations that fully reflects the supply and demand sides of the market for agricultural open space at equilibrium. Although simple, the system is exceedingly flexible and allows for household and parcel heterogeneity. We derive an empirical model directly from the...