NEW YORK -- In Tiffany Spaulding's 12 years in the pharmaceutical industry, she has worked for three companies, two of which no longer exist, and relocated to four states. Now 39 and living in Brookfield, Conn., she hasn't had a promotion in five years and says she sees no chance to advance, stuck behind a wall of baby boomers. She would quit and turn her hobby of jewelry design into a business, she says, if not for the home and school loans that eat up half her salary. Spaulding, according to a new report, is a typical member of the...