Are marginals different? Evidence from British elections 1950–2015
分析了1950-2015年英国大选数据，发现边缘选区的选票波动在预期全国结果接近或近期有选举时更独特，且部分选民能识别风向标选区。
We analyse the results of British general elections from 1950 to 2015. In our model, voting is both instrumental and expressive, and is driven both by ideology and the perceived valence of different parties. On most assumptions the model predicts that the safer the seat the lower the swing. The exception is where ideological factors are relatively dominant in instrumental voting, and valence factors are relatively dominant in expressive voting. In this case the highest swings might be in the safest seats. Alternatively swing might peak at intermediate majorities, and this is what we find when we look at swings between Conservative and Labour in seats held by one or other of these parties. We also find that marginals behave more distinctively when the national result is expected to be close or when there has been another general election recently; and that at least some voters have a sense of what is a ‘bellwether’ seat i.e. one that would be marginal in a close election. However in those seats where the main contest has been between the Conservatives and Liberal Democrats, the swing is positively related to the closeness of the contest.