In the back of my mind, I began to have doubts. Had I gone overboard in rhetorical excess? Much to my relief, after I did further research, I discovered that my initial instincts were correct.
Going to the website of the JCT and drilling down a bit, I came to the Committee's explanation of "How [It] Fulfills Its Statutory Mandate." The explanation was lengthy. It described how:
The Joint Committee staff does not operate either as a majority staff or as a minority staff. It does not have the duty of representing one particular point of view on an issue. Consequently, it is able to examine critically tax policy in all its aspects.The explanation noted that, "the Congressional tax committees need a source of independent, nonpartisan technical tax advice even when the party controlling the Congress (House and/or Senate) is the same as that controlling the Executive Branch."
Compare that charter with the way the JEC operates. The description of how the Committee operates is set forth in three scant paragraphs. Among the "research reports" it offers are such even handed offerings as "A Brief Explanation of the Economic Burden Imposed by Federal Taxes" which purports to explain how "[e]conomic theory gives policymakers solid support for resisting tax increases and preferring spending reductions as a method of reducing the federal deficit." The Democratic side of the Committee's website has similar broadsides from the other side of the partisan divide. Of course, the Democrats cannot cast their position papers as being the work of the Committee staff (apparently a group of Heritage Foundation wannabes), so, facially at least, they seem to have a lower degree of legitimacy.
The ideological slant of the JEC is apparently intentional. According to an article in the NRO by Bruce Bartlett, in the early 80's the Committee became a supporter of supply side economics. (Remember, the supporters of supply side economics have been described by Bush II economist Greg Mankiw as "charlatans and cranks." By comparison, calling them "knaves" is almost complimentary.) While Bartlett contends that the Committee currently lacks focus with "House and Senate Republicans tend[ing] to go their own way," he doesn't even attempt to make any pretense that the Committee is, as is the JCT, independent. Perhaps that's why the JCT has come under attack by such partisans as the WSJ editorial page for allegedly using incorrect predictive models (read: "predictive models that don't merely rubber stamp the economic nonsense ladled out by the Republican right").
In any event, just remember this shorthand distinction: JCT reports are reports of a single, joint, and impartial staff. JEC reports are the tendentious products of a group of determined ideologues.