Some critics of financial aid claim that, because schools are assured of receiving their fees no matter what happens to their students, they have felt free to raise their fees to very high levels, to accept students of inadequate academic ability, and to produce too many graduates in some fields of study. About one-third of students, whether or not they graduate or find jobs that match their credentials, are financially burdened for much of their lives by their debt obligations, instead of being economically productive citizens. When those former students default on their obligations, the burdens are shifted to taxpayers. Lastly, the proportion of graduates who come from poor backgrounds has actually declined since 1970.