Why is Swiss Politics so Stable?

Applying rational choice approaches of politics, I analyze why major policy changes are unlikely to occur in the Swiss political system. Legislative decision rules create durable policies by the combination of the bicameral system with the optional referendum. In contrast to normative conceptions, legislative acts tend to be more difficult to change than constitutional provisions, in spite of the qualified majority rule and the single issue requirement for constitutional amendments. Furthermore, the dominance of conservative groups in Swiss politics can be explained by the optional referendum. It is an instrument suited only for conservative groups. However, I show that this instrument is beneficial for voters.