试析英国两党制向“两个半党制”的转变

On the Transition from Two-Party System to Two-and-a-Half-Party System in the United Kingdom

近两届的英国大选结果显示,英国的两党制正在向"两个半党制"转变。其表现是第三党的崛起与两大主流政党的相对衰落。英国议会"有效政党数"的变化趋势也证明了这种转变的存在。"两个半党制"之所以出现,是因为"迪韦尔热定律"所蕴含的简单多数选举制的"二元化效应"被英国特定的制度配置、两大主流政党与社会关系的改变以及苏格兰的强地区/族裔民族主义这三个因素所削弱。展望未来,英国的"两个半党制"若持续存在,则可能会对两大政党的转型、政治效率以及政权稳定性产生一定的挑战。

The results of the recent two UK general elections show that the two-party system has been changed and a twoand-a-half-party system has emerged.This transition is illustrated by the rise of the third party and the fall of two main parties and is also evidenced by the trends of effective number of parties in Parliament.The reason why the two-and-a-half-party system emerges is that the dualization effect of simple majority system of election,as suggested by the so-called 'Duverger's Law',has been eliminated by institutional configuration,party-society relationship and Scottish regional nationalism.If this new party system persists in the UK,it will pose challenges to the transformation of the two main parties,political efficiency and regime stability.