A bottom-up change consists of grass roots change initiated by organized citizen groups that eventually changes the attitudes and policies of politics and government. A top-down change involves an opening in the three policy windows which allows policy entrepreneurs to act in a manner that they believe represents the interests of a large group of people. The change in air bag regulation is a perfect example of the top-down approach. The three streams lined up, Nader and other policy entrepreneurs spoke out, and there was little the special interest groups could do to stop the change. In this case the rising death toll has been discussed, but the money issue has not.
Auto accidents cost people money in many different ways.
This is a significant cost to society, and the figures for following years were undoubtedly similar. Given the rising death toll and the cost to society, one can easily understand how diffuse the interests were on the air bag issue. The distributive model of political policy dictates that special interest groups with large stakes act to influence sub-governments in particular ways. While this is often the de facto system of politics in specific areas, events can change in a way that changes the system of political change itself. This change is known as the knowledge-driven model.