Regarding the effects of uncertainty, it is not clear that there is much difference between a short-term provision which has been continually extended and a "permanent" provision (which, after all, is always vulnerable to repeal or modification). Compare, for example, the long-term prospects of the R&E credit (extended for over 25 years, and in one vote, 98 Senators supported making it permanent) and the "permanent" rate cut for manufacturers enacted in 2004 (does anyone think that law will be around long-term?). Also, my position would merely encourage Congress to pass legislation extending no longer than the end of the period for which costs must be accounted -- typically ten years. Thus, there is nothing to prevent Congress, consistent with this position, from passing a law to be in effect for ten years and then to extend it ten years in advance of its future expiration. In other words, there would always be a rolling ten-year period during which the law would be scheduled to be in effect. I recognize that this is unrealistic, but my only point is that if Congress is really worried about the possibly detrimental effects of uncertainty, it could address that problem while still bearing full political accountability for its actions.