The Quality and Outcomes Framework (QOF) is a Pay-for-Performance scheme introduced in England in 2004 to reward primary care providers. This incentive scheme provides financial incentives that reward the overall performance of a practice, not individual effort. Consequently, an important...

This paper provides an econometric analysis aiming at evidencing the dynamics showed by the S&P 500 market index during the period of 4 January 2001-28 April 2020, in which the subprime crisis has taken place and the COVID-19 crisis has begun. In particular, we fit a three-regime switching model...