Mandated MVNO access and MNO investment in mobile network markets: evidence from Germany and Spain

This article examines the effect of access obligation on mobile network investment. Access obligation is a form of regulated network access in wholesale markets that commits Mobile Network Operators (MNOs) to grant non-discriminatory access to Mobile Virtual Network Operators. While it is often claimed that such regulation might lower investment incentives of MNOs, this assertion has not yet been assessed by appropriate econometric methods. We implement an empirical Difference-in-Differences framework to investigate the link between access obligation and mobile network investment in Germany, where access obligation had been implemented for the 3G technology (but not for 4G and 5G), and in Spain, where access obligation had been introduced as a remedy for joint significant market power. Contrary to common claims, our results show that access obligation has not lowered mobile network investment in Germany and indeed increased investment in Spain.