When applied to a discussion of political accountability, the principal-agent theory implicitly assumes that citizens fully understand what the government is responsible for. Given their understanding of government responsibility, citizens can reward or sanction the incumbent based on the government’s performance.  This paper reexamines the above assumption and the applicability of the principal-agent theory in political accountability.  To be specific, we investigate how citizens perceive government responsibility and how the perception influences citizens’ support for the incumbent.  We argue that when they regard the government as being more responsible for social problems, citizens are more likely to hold the incumbent government accountable for its performance.  To test our hypothesis, we analyze data for a survey conducted in Kaohsiung City, New Taipei City, and Taichung City.  The results show that the voters in New Taipei City are more likely to hold the incumbent government accountable when they think the government should be more responsible for social problems.  This finding, however, does not hold in our analysis of Kaohsiung City and Taichung City.