Patent ID: 7574402

Claim:
A transaction authorization system, comprising: a computer database system storing transaction records for a plurality of past electronic payment transactions, wherein each transaction record in the database system includes a payor account identifier; A computer programmed to: perform an analysis in relation to a received request for authorization of an electronic payment transaction and determine an authorization output based on the analysis, the computer configured to receive one or more transaction-related attributes associated with the electronic payment transaction, the analysis including application of one or more checking rules of the if-then clause type comparing one or more of the transaction-related attributes to one or more predefined attribute threshold values; and programmed to access the database system and evaluate a first set of stored transaction records to determine one or more characteristic values related to the first set; wherein the characteristic values include one or more correlation values indicative of a transaction outcome correlation function, the correlation value determined from the first set of transaction records as follows: a. determining a length of time between a first transaction and a second transaction in the first set of transaction records, wherein the first transaction at a first time had a negative outcome and the second transaction at a second time had a positive outcome, wherein the first transaction and the second transaction are for the same payor account, b. repeating the determination of a length of time for at least a third transaction and a fourth transaction to create a distribution of the lengths of time; c. determining one or more transaction outcome correlation functions based on the distribution of the lengths of time, wherein the transaction outcome correlation function provides a conditional probability for predicting the outcome of a transaction according to one or more of the transaction-related attributes; d. determining a characteristic magnitude associated with the value of the conditional probability for a successful outcome; and e. setting the characteristic magnitude of the one or more transaction outcome correlation functions as a respective correlation value; and programmed to access the database system and select a second set of stored transaction records to span a time period satisfying a predetermined condition in relation to a temporal correlation length represented by at least one of the one or more correlation values, and programmed to evaluate the selected second set of transaction records and set at least one of the attribute threshold values in at least one of the checking rules based on the evaluation of the second set of transaction records.