Various forms of instability can be observed in macroeconomic and financial data including changes in variance, changes in cycle properties, or both. Traditional tests do not allow to distinguish between these different cases. This paper proposes and compares two alternative approaches. The...

The aim of this paper is to study the influence of investor attention on the French stock market activity and volatility. Following an original way, we construct a non-standard proxy of investor attention on the basis of investors' online search behavior exclusively provided by “Google...