Since the inception of Medicare Part D in 2006, mergers and acquisitions (M&A) and regulatory changes have led to increased concentration and reduced plan variety in the standalone prescription drug plan (PDP) portion of the market. We examine how this industry consolidation affects Medicare...

Using a reduced form binary econometric model, we analyze the determinants of pharmaceutical companies entry decisions into new submarkets. Our sample includes data for pharmaceutical companies over the period 1987-1998 for seven countries. Estimation is done both at the aggregate level and at a...