This thesis considers inference issues in serially correlated multilevel and panel data and presents a separate essay that examines the impact of 401(k) participation on wealth. The first chapter examines generalized least squares (GLS) estimation in data with a grouped structure where the...

The Interstate Oil and Gas Compact Commission and its member states have become increasingly concerned about environmental compliance costs for the petroleum exploration and production industry with estimated costs for 1990 at about $2 billion. Over the last decade, these costs have increased at...

We consider inference about coefficients on a small number of variables of interest in a linear panel data model with additive unobserved individual and time specific effects and a large number of additional time-varying confounding variables. We allow the number of these additional confounding...