We study the interpretation of regressions with multiple treatments and flexible controls. Such are often used to analyze stratified randomized control trials intervention arms, estimate value-added (for, e.g., teachers) observational data, leverage quasi-random assignment decision-makers (e.g. bail judges). show that these generally fail convex averages heterogeneous treatment effects, even wh...

This paper examines the relationship between foreign aid and growth in real GDP per capita as it emerges from simple augmentations of popular cross-country growth specifications. It is shown that aid in all likelihood increases the growth rate, and this result is not conditional on ‘good’ policy. There are, however, decreasing returns to aid, and the estimated effectiveness of aid is highly sen...

It is very common to see reported in applied econometric literature time series regression equations with an apparently high degree of fit, as measured by the coefficient of multiple correlation R2 or the corrected coefficient R2, but with an extremely low value for the Durbin-Watson statistic. We find it very curious that whereas virtually every textbook on econometric methodology contains exp...

This paper develops econometric tools for studying the jump dependencies between the underlying or latent spot volatilities of two assets from high-frequency observations on a fixed time interval – with a particular interest in the relationship between the individual volatilities of traded assets and the volatilities of aggregate risk factors such as the market volatility. The paper derives an ...

In this paper we combine recent advances in marginal modelling for contingency tables with the notion of copula to formulate a class of models for describing how the joint distribution of a set of ordinal response variables depends on exogenous regressors. We derive the main properties of a marginal parameterization, the global interaction copula, whose nature is essentially non parametric, and...

Article history: Received 2 September 2008 Received in revised form 13 June 2009 Accepted 16 June 2009