Decreasing purchasing power and prolonged training periods are two "worrisome trends" that affect the 41% of new chemistry Ph.D.s who take postdoc positions, according to an article  by Bethany Halford in Chemical & Engineering News (C&EN). "In chemistry, one to two years used to be the norm, but that time frame may be creeping up," Halford writes. "Some chemists tell C&EN that they are spending five or more years doing postdoctoral studies."
The median postdoc salary, per an American Chemical Society survey, has risen 11.1% between 2005 and today (from $36,000 to $40,000), Halford reports, but hasn't kept pace with inflation's 16.1% rise over the same period.
While a postdoc is essential for a shot at an academic post, it's not nearly as critical for jobs in industry. William Banholzer , chief technology officer and an executive vice president of Dow Chemical Company in Midland, Michigan, recently told  Science Careers that he considers completing a postdoc unnecessary for working at Dow. Gary S. Calabrese, senior vice president at Corning , is quoted in the C&EN article as saying that doing a postdoc is "a slight positive but by no means necessary for our jobs. … If there is a particular technical need we have and someone has the right skills, it does not matter if it came through their Ph.D. or a postdoc. Having said this, of course those with postdoctoral experience are by definition broader and have a greater chance of being a technical match for us."
Due to the lackluster job market, however, "[p]ostdocs are starting to become a substitute for real jobs," Banholzer says in the C&EN article. Some Ph.D. chemists are in fact doing multiple postdocs, which could endanger their chances of getting hired, according to an enlightening short video  spotlighted in the article.
Those who do multiple postdocs almost never get academic jobs, chemistry professor Paul Houston of the Georgia Institute of Technology in Atlanta says in the video. Banholzer adds that in industry, employers "start to wonder" about people with more than one postdoc, so it's vital to be able to show potential hirers that the experience has "made you more valuable than just biding your time."