The forthcoming article “Voting Against Your Constituents? How Lobbying Affects Representation” by Nathalie Giger and Heike Klüver is summarized here:
Do MPs listen to interest groups instead of their voters? Citizens delegate the representation of their political preferences to Members of Parliament (MPs) who are supposed to represent their interests in the legislature. However, MPs are exposed to a variety of interest groups seeking to influence how MPs cast their vote on policy proposals. Every day, thousands of lobbyists approach our legislative representatives in Washington, Brussels and any other democratic capital to influence legislative votes in their favor.
In their recent AJPS article, Giger and Klüver have examined to what extent interest groups bias the electoral connection between legislative representatives and their voters. They have employed a novel dataset that takes advantage of a unique feature of the Swiss political system, namely that public referenda are frequently called on policy proposals that are also voted on in Parliament. Using this dataset, one can directly compare voter preferences with legislative voting of 448 MPs on these issues to examine whether interest group lobbying causes MPs to cast a vote in Parliament that is not in line with what the majority of their electoral constituents wants.
Giger and Klüver show that interest groups have indeed an important impact on MP behavior in Parliament. Legislators that have strong ties with sectional groups such as business or professional associations are significantly more likely to deviate from the preferences of their voters while links with cause groups such as environmental or human rights groups in fact increase the congruence between what voters want and what their representatives do. Thus, interest groups have a differential impact on the electoral connection between citizens and their legislative representatives. Since sectional groups however typically outnumber cause groups so that significantly more MPs are lobbied by sectional groups than by cause groups, they dominate the parliamentary sphere and are therefore able to bias legislative outcomes in their favor.