Payday loans are one of the most expensive forms of credit in the world. Borrowers typically pay non annualized finance charges of 18% for loans lasting two weeks. These terms imply an annualized cost of payday loan liquidity of +.+2#& + 5 1,3/&. Truth in Lending regulations result in posted Annual Percentage Rates (APRs) for two week long loans of 18% ,0 5 .02&. Since finance charges generally do not depend on loan length, month%long and week long payday loans respectively carry annualized liquidity costs of +.+2"# + 5 0,3& and +.+2%# + 5 /.01./&.
Despite these high interest rates, ten million distinct American households borrowed on payday loans in 2002 and the industryis growth rate exceeds 15% annually (Robinson and Wheeler 2003). Consumption models offer three main complementary explanations for such a phenomenon. First, consumers may have very high discount rates, particularly in the short term (Phelps and Pollak 1968, Laibson 1997b, Frederick, Loewenstein and OiDonoghue 2002). Second, consumers may experience shocks that cause large, unanticipated variation in the marginal utility of consumption (Deaton 1991, Carroll 1992). Third, consumers may have overoptimistically rosy forecasts of the future, in regard to either their own time preferences (Akerlof 1991, OiDonoghue and Rabin 1999a) or the probability of favorable shocks (Brunnermeier and Parker 2005, Browning and Tobacman 2007).