Please research and report on the following (external research from respectable sources is required to answer this question; please ensure to cite all information):  

Please research and report on the following (external research from respectable sources is required to answer this question; please ensure to cite all information):

A. The Herfindahl–Hirschman Index (HHI) and its importance on provider payer relationships. 

B. The benefits and costs of hospital (health system) mergers.