“There is no scientist shortage,” declares Harvard economics professor Richard Freeman, a pre-eminent authority on the scientific work force. Michael Teitelbaum of the Alfred P. Sloan Foundation, a leading demographer who is also a national authority on science training, cites the “profound irony” of crying shortage — as have many business leaders, including Microsoft founder Bill Gates — while scores of thousands of young Ph.D.s labor in the nation’s university labs as low-paid, temporary workers, ostensibly training for permanent faculty positions that will never exist.