The Credit-Card-Services Augmented Divisia Monetary Aggregates

While credit cards provide transaction services, they have never been included in measures of money supply. We derive the theory to measure the joint services of credit cards and money and propose two measures of their joint services: one based on microeconomic structural aggregation theory, providing an aggregated variable within the macroeconomy; the other a credit-card-extended aggregate, optimized as an indicator to capture the contributions of monetary and credit card as nowcasting indicator of nominal GDP. The inclusion of the new aggregates yields substantially more accurate nowcasts of nominal GDP, illustrating the usefulness of the information contained in credit cards.