In themselves the nonsurvey methods may prove useful supplements to survey studies. The iterative procedure, for example, assuming the maximum possible local trade, may be used to provide estimates of upper limits on cell values. Further, in conjunction with a survey-based table, it might be used to demonstrate the possibilities for increasing local trade and the gains which might accrue. But it seems that, at the moment, there is still no acceptable substitute for a good survey-based study. This conclusion, however, is founded on a very limited test. We deliberately avoided any but grossly mechanical computations, and no systematic correction procedures are available yet. Further, our tests have been based on an aggregation procedure which completely ignores the product mix in Washington. Care in aggregation might provide quite different results—it is surprising to us that our techniques yielded acceptable regional production coefficients for over 25 per cent of the industry categories. Further tests against other survey-based tables may provide evidence of consistent differences between our estimates and survey results. These differences might be used as adjusting factors to render our estimates more reliable and to produce at least pedagogically acceptable models of regional economies.