... limit theory. See, for example, Quah (19 94), Pesaran and Smith (19 95), Kao (19 99), and Phillips and Moon (19 99). 1. 2.2 Asymptotic Analysis Throughout this book we focus on asymptotic properties, ... advanced settings. For example, in Chapters 7, 10 , and 11 we will see that as-suming fixed regressors or fixed instrumental variables in panel data models imposesoften unrealistic restrictions on ... cross section analysis the asymptotics is as the number of observations, denotedN throughout this book, tends to infinity. Usually what is meant by this statement isobvious. For panel data analysis, ...