Ball and Youdell, in 2007, identified endogenous and exogenous privatisation in the UK education system. Endogenous privatisation means the schools are privatised from within. Rather than the greater role of private companies (exogenous privatisation) the impact of marketisation policies has led to schools operating increasingly in the manner of private companies. They advertise against their competitors; there are school takeovers; parents are increasingly like consumers and there is payment by results.