This occurs because there is either an incomplete understanding or a misunderstanding of the causes of an issue on the part of the policymakers, which often leads to ineffective or detrimental policies which aggravate the issues they were implemented to correct or cause other issues to arise. Another problem Forrester notes is that some policies which may work in the long run may aggravate an issue in the short run. A successful policy according to Forrester must target the correct leverage points, in this case the aspect of the social problem which, if modified, will produce a sizeable enough effect to correct the problem.