In an effort to improve the small sample properties of generalized method of moments (GMM) estimators, a number of alternative estimators have been suggested. These include empirical likelihood (EL), continuous updating, and exponential tilting estimators. We show that these estimators share a common structure, being members of a class of generalized empirical likelihood (GEL) estimators. We us...

In an effort to improve the small sample properties of generalized method of moments (GMM) estimators, a number of alternative estimators have been suggested. These include empirical likelihood (EL), continuous updating, and exponential tilting estimators. We show that these estimators share a common structure, being members of a class of generalized empirical likelihood (GEL) estimators. We us...

We present a new estimator for causal effects with panel data that builds on insights behind the widely used difference-in-differences and synthetic control methods. Relative to these methods we find, both theoretically empirically, this “synthetic difference-in-differences” has desirable robustness properties, it performs well in settings where conventional estimators are commonly practice. st...

When the overidentifying restrictions of the constant-effect linear instrumental variables model fail, common IV estimators converge to different probability limits. I characterize the estimands of two stage least squares, two step GMM, and limited information maximum likelihood as functions of the single-instrument estimands from the just-identified IV regressions which consider each instrumen...

In this paper we test for the inclusion of the bid-ask spread in the consumption CAPM, in the UK stock market over the time period of 1980-2000. Two econometric models are used; first, Fisher’s (1994) asset pricing model is estimated by GMM, and secondly, the VAR approach proposed by Campbell and Shiller is extended to include the bid-ask spread. Overall the statistical tests are unable to reje...

We analyze the limiting distribution of Rivers and Vuong’s (2002) statistic for choosing between two competing dynamic models based on a comparison of GMM minimands. It is shown that: (i) if both models are misspecified then the statistic has a standard normal distribution under the null hypothesis of equal fit but the ranking could be determined by the choice of the weighting matrix; (ii) if b...

We use a panel of 155 countries for 1970-2010 to study (two-way) causality between government spending, revenue and growth. Our results suggest the existence of weak evidence supporting causality from expenditures or revenues to GDP per capita and provide evidence supporting Wagner’s Law. JEL: C23, E62, H50.

This paper tests whether consumption pattern in Korea exhibits a time-inconsistent discounting behavior using a quasi-hyperbolic Euler equation estimated by the generalized method of moments (GMM). In particular, we examine whether consumers change their discounting behavior during financial crises in 1997 and 2008. The estimation results show that Korean consumers exhibit a time-inconsistent q...

This paper proposes a new class of HAC covariance matrix estimators. The standard HAC estimation method re-weights estimators of the autocovariances. Here we initially smooth the data observations themselves using kernel function based weights. The resultant HAC covariance matrix estimator is the normalised outer product of the smoothed random vectors and is therefore automatically positive sem...

In models with potential weak identification researchers often decide whether to report a robust confidence set based on an initial assessment of model identification. Two-step procedures of this sort can generate large coverage distortions for reported confidence sets, and existing procedures for controlling these distortions are quite limited. This paper introduces a generally-applicable appr...