The question we face as designers of educational programs is how to structure them in light of the longer times that PhDs take and the fact that some students who start these programs may rationally choose not to complete them. The answer may be to divide current PhD programs into two chunks. The first chunk would be a two-year master’s degree focused on taking advanced courses. The second chunk—appropriate for only a subset of master’s students—would be a research degree culminating in the PhD.For quite some time my advice to most of my undergraduate students about pursuing a Ph.D. in economics has been consistent with Mankiw's suggestions. I think it is worth reading his entire post.
PETER BOETTKE also notes Mankiw's suggestions and offers:
Back to Mankiw's reflections --- at GMU we have a strong MA program, and within that a track that the Mercatus Center supports that has done an excellent job of placing students in highly leveraged positions in public sector, public policy think-tanks, and the private sector, and our full-time population of PhD students on funding graduates students in 4 to 5 years, and has a high percentage of graduation. In many ways, we are already doing what Mankiw recommends in terms of structural changes to graduate programs in economics to maximize their educational value to their customers.I think that for almost a decade now I have been telling my students interested in economics graduate study that if I started all over today, given all that I've learned since about 1975, I would probably put George Mason at the top of my list.