This paper proposes a sign-based portmanteau test for diagnostic checking of ARCH-type models estimated by the least absolute deviation approach. Under the strict stationarity condition, the asymptotic distribution is obtained. The new test is applicable for very heavy-tailed innovations with...

This article proposes Cramer-von Mises (CM) and Kolmogrove-Smirnov (KS) test statistics based on the signs of a time series to test the null hypothesis that the series is a martingale difference sequence (MDS) with conditional heteroscedasity. Both of test statistics allowing for...

Random Utility Models of recreation demand are widely used to relate demand and value to the characteristics of recreation sites. Although some kinds of endogeneity problems have been studied in previous literature, no study has addressed the potential problem with site characteristics that are...

A growing number of firms are strategically utilizing IT and the Internet to provide online services to consumers who buy their products. Online services differ from traditional services, such as maintenance services, because they often promote interactivity among the firm’s customers and...