From Poor Economics by Esther Duflo and Abhijit Bannerjee

There is potentially another reason the poor may hold on to beliefs that might seem indefensible: When there is little else they can do, hope becomes essential. One of the Bengali doctors we spoke to explained the role he plays in the lives of the poor as follows: “The poor cannot really afford to get treated for anything major, because that involves expensive things like tests and hospitalization, which is why they come to me with their minor ailments, and I give them some little medicines which make them feel better.” In other words, it is important to keep doing something about your health, even if you know that you are not doing anything about the big problem. In fact, the poor are much less likely to go to the doctor for potentially life-threatening conditions like chest pains and blood in their urine than with fevers and diarrhea. The poor in Delhi spend as much on short-duration ailments as the rich, but the rich spend much more on chronic diseases.34 So it may well be that the reason chest pains are a natural candidate for being a bhopa disease (an older woman once explained to us the dual concepts of bhopa diseases and doctor diseases—bhopa diseases are caused by ghosts, she insisted, and need to be treated by traditional healers), as are strokes, is precisely that most people cannot afford to get them treated by doctors.