Like any financial institution, credit unions have the financial resources. Like the credit cooperatives, credit unions form associations of a higher level, which are called corporate credit unions. In the U.S. credit unions timely and full repayment of loans is a common phenomenon. Unpaid and delinquent loans are not more than 3% of their amount. Among the U.S. credit unions, there are three groups that differ in terms of assets, shareholders, and business services. Until the 70's there was a proliferation of the U.S. credit unions due to the increase of their number and the number of shareholders, although it must be acknowledged that there was also and a qualitative growth. Credit unions encourage the proper use of shareholders savings, developing social programs (education, health, recreation, housing, etc.). A potential new member of a credit union must submit a recommendation of shareholders in which the referee becomes a warrant of a future member of the credit union.