Evaluating Alternative Regional Planning Models: Comment

In their article "Evaluating Alternative Regional Planning Models," John B. Crihfield and Harrison S. Campbell, Jr. evaluate the relative performance of 2 alternative regional economic models, REMI and IMPLAN, in terms of their ability to estimate economic impacts for small regions. They conclude that IMPLAN's outcomes, on balance, are more plausible than those for REMI. It is argued that the authors did not carry out comparable experiments with the 2 models, and that had they done so, the outcome comparisons would have shown different results, and would have led to different conclusions. When correction is made for Crihfield and Campbell's errors, some of the differences between the models used in the evaluation virtually disappear. The basic conclusion of Crihfield and Campbell is without foundation. Instead, the 2 models appear to show similar input-output impact results when properly implemented, particularly when corrections are made so that the same industries are being compared.