Stock market efficiency before and after a financial liberalisation reform:do breaks in volatility dynamics matter?

This article focuses on the deviations from normality of stock returns before and after a financial liberalisation reform, and shows the extent to which inference based on statistical measures of stock market efficiency can be affected by not controlling for breaks. Drawing from recent advances in the econometrics of structural change, it compares the distribution of the returns of five East Asian emerging markets when breaks in the mean and variance are either (i) imposed using certain official liberalisation dates or (ii) detected non-parametrically using a data-driven procedure. The results suggest that measuring deviations from normality of stock returns with no provision for potentially existing breaks incorporates substantial bias. This is likely to severely affect any inference based on the corresponding descriptive or test statistics.

Taking strategy seriously:responsibility and reform for an important social practice

Strategy is a pervasive and consequential practice in most Western societies. We respond to strategy's importance by drawing an initial map of strategy as an organizational field that embraces not just firms, but consultancies, business schools, the state and financial institutions. Using the example of Enron, we show how the strategy field is prone to manipulations in which other actors in the field can easily become entrapped, with grave consequences. Given these consequences, we argue that it is time to take strategy seriously in three senses: undertaking systematic research on the field itself; developing appropriate responses to recent failures in the field; and building more heedful interrelationships between actors within the field, particularly between business schools and practitioners.