In a 1991 evaluation of the usefulness of policy research Ronald Brunner wrote that “most preventable errors of policy analysis stem from the analyst’s perspective; as the analyst simplifies a problem to make it tractable for analysis and action, some important part of the relevant context is misconstrued or overlooked altogether.” Errors in policy analysis, Professor Brunner tells us, can have real-world effects. “The analytical error – what is misconstrued or overlooked – becomes apparent only in retrospect, after resources have been committed and the unintended and often adverse results start coming in.”