The Impact of Market Growth on Delivery Times: Evidence from JD.com

We analyze 214,726 shipments made by the e-commerce platform JD. We find that customers who joined the JD platform more recently receive slower deliveries than legacy customers who joined longer ago do. Specifically, we find that every additional year a customer has been on the platform decreases their average delivery time by about 0.67 hours. Our results suggest that as JD's traditional demand centers have become saturated, it has pursued growth in progressively harder-to-reach areas with less-developed distribution infrastructure, which makes its supply chain slow down as it grows.