Dyadic representation in a Westminster system

Is policy representation in contemporary Westminster systems solely a function of programmatic national parties, or does the election of Members of Parliament via single member districts result in MPs whose policy positions are individually responsive to public opinion in their particular constituency? To answer this question, we generate new measures of constituency opinion in Britain and show that, in three different policy domains and controlling for MP party, the observed legislative behaviour of MPs is indeed responsive to constituency opinion. The level of responsiveness is moderate, but our results do suggest a basic constituency-MP policy bond which operates in addition to the well-known bond between voters and parties.