Interesting article in the National Review:  A Dynamic Idea Gains Momentum; Tracking a Modest Budget-Scoring Breakthrough, by Greg Kaza:

President Bush’s 2007 budget, released in February, proposed spending $513,000 for a dynamic-analysis unit within the Treasury Department. The unit would not initially conduct dynamic analysis or scoring — which represents an attempt to summarize, as a cost estimate, the impact of policy changes on revenue estimates — but it would advise federal policymakers on how tax-rate revisions might affect economic aggregates. That’s an improvement over the current state of affairs, and a modest breakthrough for economists who argue that static models fail to capture the dynamic effects of tax cuts.

The congressional Joint Committee on Taxation and the Treasury Department’s Office of Tax Analysis develop revenue estimates, and in the process they use static models that assume some aggregates will not be altered by rate revisions. Dynamic scoring, however, attempts to measure the feedback-effects ignored in these models — those feedback-effects potentially becoming excellent ammunition for supply-side policymakers and tax-cut advocates.