Recently I read an article on the whining PHD students. The central issue was whether the universities are producing PHDs at rate higher than the demand. Today, if we look at the current trend, a major chunk of PHDs actually get jobs in R&D sectors in industry or other research labs. Another not so insignificant portion joins academia and pursue teaching career. Only a small percent shows entrepreneurial skills and setup their own companies.
The demand in the industry fluctuates based on the global economic situation. However, in academia the situation is different. According to an article in Nature, the number of science doctorate students grew by 40% each year from 1998 to 2008. The not so increasing demand in the industry for positions in research labs makes it a convenient option for graduating doctorates to join academia and teach. They in turn produces more doctorates. This has a nature of exponential growth of PHD students. More PHD students does not necessarily imply higher quality research and has its adverse effect on limited scintific grants and funds. So this becomes an open question whether the number of PHD students graduating the PHD intake each year should be regulated by the schools keeping in mind the industry scenario.