Interoperability for number-independent interpersonal communications services under the DMA: More harm than good?

Abstract

The Digital Markets Act (DMA) is a cornerstone of European digital platform regulation. Gatekeepers are required to enable interoperability of their number-independent interpersonal communications services (NI-ICS), which are designated as core platform services (CPS) like e.g. messaging ser-vice WhatsApp. To this end the DMA defines a three-stage implementation of interoperability, start-ing with simple bilateral text communication with further features to follow over a period of four years (DMA, Art. 7(2)).
Using a consumer survey in Germany with 2,826 respondents, this study examines the potential effect of interoperability on consumer preferences for using specific NI-ICS. As NI-ICS are subject to network effects, demand tends to gravitate towards services with a larger user base, which has re-sulted in a highly concentrated market. Horizontal interoperability could counteract such tendencies towards concentration. However, this desired effect is highly dependent on the willingness of con-sumers to use NI-ICS in an interoperable manner, and which NI-ICS they choose to use as a result of interoperability.
There are two main findings from our consumer survey:
First, we find that almost all NI-ICS users in Germany tend to use NI-ICS (97%), which are designat-ed as CPS. WhatsApp alone is currently used by around 93% of NI-ICS users and is typically ac-cessed on a daily basis. In contrast, only 50% of NI-ICS users use an alternative (non-gatekeeper) service. Overall, alternative services are used less frequently and tend to play a subordinate role in the interpersonal communication of German users.
Second, very few NI-ICS users are opposed to interoperability, 64% consider it useful, and at each stage of implementation more than half of respondents indicate that they would use interoperability - at least in some cases – to communicate with specific contacts, via certain functions or via certain services. However, the majority of NI-ICS users that intend to adopt interoperability expect to contin-ue to use gatekeeper services to the same extent as they do now. In addition, the proportion of users who intend to use gatekeeper services to a greater extent than before the introduction of interopera-bility slightly outweighs the proportion of users who intend to use these services less. With regard to the use of alternative NI-ICS, the proportion of users who say they will use alternative NI-ICS less than before the introduction of interoperability is about twice as high as the proportion of users who intend to use these services more.
Therefore, interoperability as mandated by the DMA could lead to a reduction in the use of alternative NI-ICS by those NI-ICS users who choose to enable interoperability. It may even increase the incen-tive to use gatekeeper services, thereby contributing to the strengthening of gatekeeper ecosys-tems. Our results therefore call into question the incentive for alternative NI-ICS providers to de-mand interoperability from gatekeepers in the first place. Overall, our analysis suggests that the effect of the horizontal interoperability obligation for NI-ICS in the DMA may be contrary to the in-tended effect, or at least will not mitigate the concentration tendencies in the market for NI-ICS.

Keywords: Number-independent communications services, Digital Markets Act, interoperability, consumer sur-vey

JEL Classification: D12, O33, L86