Microeconometrics researchers have increasingly realized the essential need to account for any within-group dependence in estimating standard errors of regression parameter estimates. The typical preferred solution is to calculate cluster-robust or sandwich standard errors that permit quite...

In this paper we survey methods to control for regression model error that is correlated within groups or clusters, but is uncorrelated across groups or clusters. Then failure to control for the clustering can lead to understatement of standard errors and overstatement of statistical...

In this paper we survey methods to control for regression model error that is correlated within groups or clusters, but is uncorrelated across groups or clusters. Then failure to control for the clustering can lead to understatement of standard errors and overstatement of statistical...

Our empirical investigation confirms the common belief that retail gasoline prices react more quickly to increases in crude oil prices than to decreases. Nearly all of the response to a crude oil price increase shows up in the pump price within 4 weeks, while decreases are passed along gradually...

Researchers have increasingly realized the need to account for within-group dependence in estimating standard errors of regression parameter estimates. The usual solution is to calculate cluster-robust standard errors that permit heteroskedasticity and within-cluster error correlation, but...

This paper reconsiders the equity issue in Swedish health care utilisation previously analyzed by Gerdtham (Health Economics 6, 303-319, 1997) within the framework of the standard two-part model. Departing from the user/nonuser distinction, we use the more flexible framework of the finite...