A behind-the-scenes blog about research methods at Pew Research Center. For our latest findings, visit pewresearch.org. Identifying causal relationships from observational data is not easy. Still, ...

A simulation study is designed to evaluate the sensitivity of inference in a Vector Autoregression in which the variables of interest (GNP, the money stock, the price level, and a short-term interest ...

Let P = (pjk) be the transition matrix of an ergodic, finite Markov chain with no cyclically moving sub-classes. For each possible transition (j, k), let Hjk(x) be a distribution function admitting a ...