Professor Jungbin Hwang and his co-author Yixiao Sun have had their paper, “Simple, Robust, and Accurate F and t Tests in Cointegrated Systems,” accepted by Econometric Theory  as a lead article in a future issue.

In this paper, they propose new, simple, and more accurate statistical tests in a cointegrated system that allows for endogenous regressors and serially dependent errors. The approach involves first transforming the time series using orthonormal basis functions in L-2 space, which have energy concentrated at low frequencies, and then running an augmented regression based on the transformed data and constructing the test statistics in the usual way. The F and t tests developed in this article, are extremely simple to implement have more accurate size in finite samples than existing tests such as the asymptotic chi-squared and normal tests based on the fully modified OLS estimator of Phillips and Hansen (1990) and can be made as powerful as the latter test.