Event studies are increasingly found in the applied finance literature. They are employed to analyse the market reaction to events and thus to investigate market efficiency. The paper is concerned with misspecification testing of the single-index market model which is conventionally employed to...

In a recent article in this journal Hitiris used panel data for ten EC countries to analyse the determinants of aggregate health care expenditure. This comment shows that the model was plagued by a spurious regression problem. The data are reexamined using standard unit root and cointegration...