People typically don't start a PhD with the expectation of making more money. They start it because they think research will be interesting. Many people drop o

People typically don't start a PhD with the expectation of making more money. They start it because they think research will be interesting. Many people drop out once they realize that doing a PhD is not for them. I've seen estimates that the average dropout rates are something like 40-50%. Many of them are high achievers, who are very good at completing well-defined tasks given to them, but who don't enjoy working on more open-ended problems. Others are driven out by the intense pressure and the expectations of long working hours that are present in some labs, particularly in elite universities. And some, in countries where people doing PhD are considered students rather than junior professionals, cannot tolerate the poverty imposed on them.