Representative democracy translates the preferences of the electorate into policy outcomes. Individual voters do not directly vote on policy; rather, their elected representatives create and establish policy. How well do the institutions of representative democracy translate the preferences of the electorate into policy? Is there any systematic bias in a representative democracy system? After formulating a series of computational models it appears that the degree to which legislative districts are ‘gerrymandered’ with respect to preferences about the policy is a source of policy bias. To illustrate the phenomenon, household income is used as a proxy for voters’ preferences with respect to redistribution. Even when the majority of voters are in favor of redistribution, if districts are constructed with a sufficient level of conservative gerrymandering, the policy outcome under representative democracy will favor far less redistribution than the policy outcome under direct democracy.