This paper defines and analyzes the impulse response function for conditional volatility in GARCH models. It first derives the function from a vector autoregressive and moving average representation of the GARCH models and obtains the corresponding standard errors from the first-order...

This article investigates empirically how returns and volatilities of stock indices are correlated between the Tokyo and New York markets. Using intradaily data that define daytime and overnight returns for both markets, we find that Tokyo (New York) daytime returns are correlated with New York...

This paper investigates empirically how returns and volatilities correlated between Tokyo and New York stock indices (Nikkei 225 and s&p500). First, intradaily data are used, so that daytime and overnight returns are defined for both markets. Tokyo daytime hours overlap with New York overnight...