Abstract The European Electronic Communications Code (EECC) enables competent authorities to introduce interoperability obligations also for number-independent interpersonal communications services (NI-ICS) such as Facebook Messenger, LINE, Skype, WeChat and WhatsApp. Under such an obligation, consumers could interact not just with users of the NI-ICS where they have a user account themselves, but also with users of all then interoperable NI-ICS. While with traditional electronic communications services (ECS) economic theory and consumer interests align as regards interoperability since multi-homing across various operators is the exemption, it is not yet clear whether that is also true for NI-ICS for which multi-homing is the norm. Our paper draws on an online survey of n = 2044 consumers in Germany covering traditional ECS, email and 22 other NI-ICS to address this issue from a consumer point of view. We find that people proactively use the boundaries between communications services to compartmentalize their social contacts according to relationship closeness. Our finding echoes indications provided in a rich stream of computer-mediated communication (CMC) research and in particular psychological theories of relationship development. Specifically, people appear to follow a finely tuned cultural code implying a hierarchical order of communications services used depending on the closeness of the contacts. Consequently, our results provide a complementary explanation of how and why certain groups of social ties converge to a specific (set of) communications service(s) beyond network effects and shed a critical light on current policy debates around an interoperability obligation for interpersonal communications applications. They highlight that an interoperability obligation for NI-ICS would likely not be in line with consumer interests.

中文翻译：

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人际通信服务的互操作性——消费者视角

摘要 欧洲电子通信规范 (EECC) 使主管当局能够为与号码无关的人际通信服务 (NI-ICS)，例如 Facebook Messenger、LINE、Skype、微信和 WhatsApp 引入互操作性义务。在这种义务下，消费者不仅可以与他们自己拥有用户帐户的 NI-ICS 用户进行交互，还可以与所有可互操作的 NI-ICS 用户进行交互。虽然传统的电子通信服务 (ECS) 经济理论和消费者利益在互操作性方面是一致的，因为跨不同运营商的多宿主是例外，目前尚不清楚这是否也适用于多宿主是 NI-ICS规范。我们的论文借鉴了对德国 n = 2044 名消费者的在线调查，涵盖了传统的 ECS，电子邮件和其他 22 个 NI-ICS 从消费者的角度解决这个问题。我们发现人们主动利用通信服务之间的界限，根据关系的密切程度来划分他们的社交联系。我们的发现与丰富的计算机中介传播 (CMC) 研究，特别是关系发展的心理学理论中提供的迹象相呼应。具体来说，人们似乎遵循精心调整的文化代码，这意味着根据联系人的密切程度使用的通信服务的等级顺序。最后，我们的结果提供了对某些社会联系群体如何以及为什么会聚到网络效应之外的特定（一组）通信服务的补充解释，并为当前围绕人际通信应用程序的互操作性义务的政策辩论提供了重要的启示。他们强调 NI-ICS 的互操作性义务可能不符合消费者的利益。