from a bank or ATM, casino chips, and some payments to the government (and any transaction that looks in the bank's discretion like a cash swap, such as a payment on multiple invoices). In effect, the interest rate charged on purchases is subsidized by other profits to the bank. Default rate Many US banks since 2000 and 2009 had a contractual default rate (in the U.S., 2005, ranging from 10to36%), which is typically much higher than the regular APR. The rate took effect automatically if any of the listed conditions occur, which can include the following: one or two late payments, any amount overdue beyond the due date or one more cycle, any returned payment (such as an NSF check), any charging over the credit limit (sometimes including the bank's own fees), andin some casesany reduction of credit rating or default with another lender, at the discretion of the bank. In effect, the cardholder is agreeing to pay the default rate on the balance owed unless all the listed events can be guaranteed not to happen. A single late payment, or even a non-reconciled mistake on any account, could result in charges of hundreds or thousands of dollars over the life of the loan. These high effective fees create a great incentive for cardholders to keep track of all their credit card and checking account balances (from which credit card payments are made) and for keeping wide margins (extra money or money available). However, the current lack of provable "account balance ownership" in most credit card and checking account designs (studied between 1990 and 2005) make these kinds of "penalty fees" a complex problem, indeed. New US statutes passed in 2009 limit the use of default rates by allowing an increase in rate on purchases already made only to accounts that have been over 60 days late. Variable rate Many credit card issuers give a rate that is based upon an economic indicator published by a respected journal. For example, most banks in the U.S. offer credit cards based upon the lowest U.S. prime rate as published in the Wall Street Journal on the previous business day to the start of the calendar month. For example, a rate given as 9.99% plus the prime rate will be 16.99% when the prime rate is 7.00% (such as the end of 2005). These rates usually also have contractual minimums and maximums to