Patent ID: 8025220

Claim:
A computer program product, tangibly embodied in a computer-readable medium, the computer program product being operable to cause data processing apparatus to perform operations comprising: initiating a determination of one or more possible base locations of a cardholder of a payment card; associating transactions of the cardholder with a plurality of merchant customer base location profiles, each of the merchant customer base location profiles characterizing geographic base locations of a plurality of customers with which a merchant has had a transaction; deriving from the merchant customer base location profiles the one or more possible cardholder base locations; and providing the one or more possible base locations; wherein the merchant customer base location profiles comprise geographic distributions smoothed in accordance with the equation: L ( z i |m k )=(1 −w k ) P ( z i )+( w k P ( z i |m k )); where: z i represents a ZIP code ‘i’; m k represents a merchant ‘k’; L(z i |m k ) is an estimate of the probability that the base location of a customer of merchant k is ZIP code i; w k is computed in accordance with the function w k =C(m k )/(C(m k )+a); P(z i ) is ab overall probability of a cardholder having a base location of a ZIP code i; and P(z i |m k ) is a measured probability of a cardholder having a base location of a ZIP code i for a merchant k; wherein P(z i |m k )=C(z i |m k ), and C(z i |m k ) is the number customers with stated base location ZIP code i for a merchant k or the number transactions by customers with stated base location ZIP code i for a merchant k.