Thanks. I respectfully disagree.
First, if this was the intention, I wish the analysts had made that more apparent and up-front than a footnote.
Even with a more prominent caveat, however, I don't think the graph showing a theoretical shortfall due to fuel economy standards was very responsible or helpful. It is likely to be replicated over and over without a footnote, distracting policymakers at worst and muddling the issues at best.
Fuel economy standards may exacerbate the huge and growing transrpotation finance problem in the out-years, but the bigger and more immediate issue by far is policymaker inability to confront and remedy what President Reagan called the need for "revenue enhancement." Our transportation program is hostage to virulent and wrongheaded anti-tax ideology that has overtaken Washington and helped trump anincrease in the federal gas tax for almost 20 years (meanwhile, inflation certainly doesn't stand still). That's the big issue here.
The responsible thing for CBO to do rather than throwing a potential red herring into an already dysfunctional debate is to issue analyses, reports, statements, you name it, about the chronic and growing insolvency of the national transprotation program due to revenue shortfalls, and the tools that can be most effective in addressing it.
Happy to loan CBO, and any other responsible economists, a soapbox if it helps.