"Close the revolving door between the S.E.C. and Wall Street. At every turn we keep coming back to an enormous barrier to reform: Wall Street’s political influence. Its influence over the S.E.C. is further compromised by its ability to enrich the people who work for it. Realistically, there is only so much that can be done to fix the problem, but one measure is obvious: forbid regulators, for some meaningful amount of time after they have left the S.E.C., from accepting high-paying jobs with Wall Street firms."