Nate Kreuter cautions would-be PhD students about being over-optimistic about job prospects:
What is so impossible for many graduate students to understand is that everybody in their cohort is just as smart and hardworking as they themselves are. At the graduate level, the smarts and diligence that once set students apart from their undergraduate peers will no longer set them apart, but merely allow them to keep up. It is almost impossible for many beginning graduate students to grasp that having above average intelligence and an unimpeachable work ethic will mean only that they are average graduate students. That's quite a shock to some people.
This chart, showing the unemployment rate by education level, is a necessary counterweight to Kreuter's warning. Erik Loomis is in related territory.
The Dish 