This paper investigates the potential problem of ‘pseudo-exogenous’ instruments in regression models. We show that the performance of Hausman test is deteriorated when the instruments are asymptotically exogenous but endogenous in finite samples, through Monte Carlo simulations.

The Breusch-Godfrey’s LM test is one of the most popular tests for autocorrelation. However, it has been shown that the LM test may be erroneous when there exist heteroskedastic errors in regression model. Some remedies recently have been proposed by Godfrey and Tremayne (2005) and Shim et al....

In this article, we study the impact of an abrupt change in variance on the Breusch-Godfrey's LM test for autocorrelation. It is demonstrated by Monte Carlo simulations that a break in variance can generate spurious rejections of the null hypothesis of no serial correlation. Hence, a researcher...

The aim of this study is to analyse the relationship between technological change and the educational wage premium in Korea. The main findings are as follows. First, the changes in educational wage premium were mostly affected by shifts in the supply of college graduates from 1983 to 1993 while...