Jennifer Rohn's solution to the problems of postdoctoral careers does not add up (Nature 471, 7; 2011).

Most fields of science are at a steady state of funding, or worse, so paying for new professional postdocs would require cuts to training postdoc positions. But a career spans 30–40 years, so each career postdoc would replace 6–20 training postdocs. If there were enough professional postdoc positions to make a difference, there would be a huge reduction in the number of training postdocs. The scrap heap would be larger: each rescued professional postdoc would be replaced by several new PhDs with no chance of finding a postdoc position.

The only other way to avoid a scrap heap would be to restrict the number of people who start PhDs, which raises a host of other complex issues.