The social mechanisms approach to the social sciences aligns well with two key intellectual practices, experiments and policies. In an experiment we are interesting in testing whether a given factor has the effect it is thought to have. In a policy design we are interested in affecting an outcome of interest by manipulating some of the background conditions and factors. In both instances having a theory of the mechanisms in play in a domain permits us to frame our thinking better when it comes to designing experiments and policies.
Let's say that we are interested in reducing the high school dropout rate in a high-poverty school. We may have a hypothesis that one important causal factor that leads to a higher likelihood of dropping out is that high-poverty students have a much greater burden of family and social problems than students in low-poverty populations. We might describe the mechanism in question in these terms: