A growing body of research has examined the uptake of social media by politicians, the formation of communication ties in online political networks, and the interplay between social media and political polarization. However, few studies have analyzed how social media are affecting communication in parliamentary networks. This is especially relevant in highly fragmented political systems in which collaboration between political parties is crucial to win support in parliament. Does MPs’ use of social media foster communications among parliamentarians who think differently, or does it result in like-minded clusters polarized along party lines, confining MPs to those who think alike? This study analyzes the formation of communication ties and the degree of homophily in the Dutch MPs’ @mention Twitter network. We employed exponential random graph models on a 1-year sample of all tweets in which Dutch MPs mentioned each other (N = 7,356) to discover the network parameters (reciprocity, popularity, and brokerage) and individual attributes (seniority, participation in the parliamentary commissions, age, gender, and geographical area) that facilitate communication ties among parliamentarians. Also, we measured party polarization by calculating the external–internal index of the mentions. Dutch MPs’ communication ties arise from network dynamics (reciprocity, brokerage, and popularity) and from MPs’ participation in the parliamentary commissions, age, gender, and geographical area. Furthermore, there is a high degree of cross-party interactions in the Dutch MPs’ mentions Twitter network. Our results refute the existence of “echo chambers” in the Dutch MPs’ mentions Twitter network and support the hypothesis that social media can open up spaces for discussion among political parties. This is particularly important in fragmented consensus democracies where negotiation and coordination between parties to form coalitions is key.

越来越多的研究调查了政治人物对社交媒体的使用，在线政治网络中沟通纽带的形成以及社交媒体与政治两极化之间的相互作用。但是，很少有研究分析社交媒体如何影响议会网络中的交流。这在高度分散的政治体系中尤其重要，在这种政治体系中，政党之间的合作对于赢得议会的支持至关重要。国会议员对社交媒体的使用是否会促进持不同意见的议员之间的交流，还是会导致志同道合的党派沿着党派两极分化，从而将国会议员局限在有相同想法的议员手中？这项研究分析了荷兰国会议员@mention Twitter网络中的沟通纽带和同质程度。ñ= 7,356）以发现网络参数（互惠，受欢迎程度和经纪人）和个人属性（资历，参加议会委员会，年龄，性别和地理区域）来促进议员之间的联系。另外，我们通过计算提及的外部-内部指数来衡量当事方的两极化。荷兰国会议员的沟通联系源于网络动态（互惠，经纪和知名度）以及国会议员参与议会委员会，年龄，性别和地理区域的原因。此外，荷兰国会议员提到的Twitter网络之间存在高度的跨党派互动。我们的结果驳斥了荷兰国会议员提到的Twitter网络中“回声室”的存在，并支持以下假设：社交媒体可以为政党之间的讨论提供空间。在零散的共识民主制中，这一点尤其重要，在民主制中，各方之间的谈判与协调以建立联盟为关键。