30/03/26
- Documents de travail
This paper combines high-frequency mobile phone location data with card transaction records, to examine the relationship between the number of individuals present in a zone ('real-time population') and economic transactions. Using data from the metropolitan area of Lyon, France's second-largest urban area, and a Poisson Pseudo-Maximum Likelihood estimator, we estimate the elasticity of transactions with respect to a real-time count of individuals present in each of over one thousand zones. We document three key findings: (1) consumption responsiveness varies systematically across time and space, with elasticities peaking at 1.08 on Saturday midday but declining to 0.98 on Sunday and ranging from 1.04 in urban cores to 0.84 in peripheries; (2) spatial frictions reduce transaction flows by 2% per 1% increase in distance from home; and (3) sectoral heterogeneity, where essential goods (e.g., food retail) consistently outperform discretionary sectors (e.g., arts and entertainment). Together, these results underscore how temporal, spatial, and sectoral factors jointly shape economic activity.
