Punctuated-equilibrium theory seeks to explain a simple observation: political processes are generally characterized by stability and incrementalism, but occasionally they produce large-scale departures from the past. Stasis, rather than crisis, typically characterizes most policy areas, but crises do occur. Large-scale changes in public policies are constantly occurring in one area or another of American politics and policymaking as public understandings of existing problems change. Important governmental programs are sometimes altered dramatically, even if most of the time they continue as they did in the previous year. While both stability and change are important elements of the policy process, most policy models have been designed to explain, or at least have been most successful at explaining, either the stability or the change. Punctuated-equilibrium theory encompasses both.