With the US presidential campaign focusing so much on character (Obama's embrace of his racist preacher, Clinton's embellished "experience," McCain's unpredictable "maverick" tendencies), one can lose track of some very real issues that divide the candidates. These aren't limited to the economic issues, but that's today's focus. This week Congressional Democrats tied themselves squarely to the anti-free trade crowd with Speaker Pelosi refusing a vote on the Columbian free trade agreement (which Bill was for before Hillary was against). Hovering just under the radar is, aguably, the biggest divide: the Bush tax cuts. Democrats only accepted the cuts because they included in the package a provision that automatically restores the original tax rules and rates at the end of 2010 unless another law supersedes the one on the books. Democrats have loudly proclaimed the tax cuts as a Republican give-away of the federal treasury while Republicans crow that the cuts ended the recession that began in the last year of the Clinton presidency and is needed to sustain our economic growth.

The April 21 edition of National Review (subscription required) examines the historic tax take of the national governments of the US and its OECD partners. An excerpt illustrates, but please keep reading because I'd like to draw a parallel to an issue regarding salt. NR's Kevin Hassett wrote:

As reporters sort through these debates, they must write at a far lower level of sophistication than that of the studies in question. Since New York Times readers don't know econometrics, they are instead offered pseudo-analysis. The economists who agree with supply-side economics are generally described in terms to suggest that they are nut jobs. Those who disagree with supply-siders are "distinguished professors" or "senior fellows" at "nonpartisan" institutes. We are invited to judge, not the arguments, but the reasonableness of those who make them - and it is clear what our judgment is supposed to be. But interestingly enough, it's possible to determine with some precision whether a policy has been formulated by nut jobs. To see how, consider the following statement: "U.S. fiscal policy in recent years has deviated wildly from fiscal policy in other developed nations." If that's true, one can presumably make the case that U.S. policymakers have ignored policy norms. (This is of course just what one would expect nut jobs to do.) If the claim is false, however, then it's rather harder to claim that American fiscal policy is in the hands of kooks.

Let's apply that method to the question of income-tax cuts. The nearby chart depicts recent trends in the share of GDP that governments collect through income taxes. The purple line represents the U.S.; the blue line represents the average for large developed nations in the OECD, excluding the U.S. And the story is clear: For most of recent history, the U.S. share was about equal to that of the OECD generally. It did deviate wildly at one point - in the second term of President Clinton, when the U.S. was collecting a markedly higher percentage of its GDP in income-tax revenue than were its fellow OECD members. But the Bush tax cuts returned us to normalcy.

The "salt" issue? The policy debates over whether the entire population should be encouraged to reduce dietary salt often comes across as a debate with an empty chair. Proponents of this intervention are content to point to their accepted "expert" status and insist that their informed opinion should determine the policy question. These are the "distinguished professors" etc of Mr. Hassett's narrative. By no means all, but some of these activists have tried to marginalize the equally-distinguished experts who argue that no evidence shows low salt diets will improve public health. They duck the issue and try to dismiss opposing scientists as somehow less informed or, surely, more biased -- in short, akin to the "nut jobs" Mr. Hassett describes (though none of them have stooped that far to date).

The parallel? Mr. Hassett graphs the data. That's what we should be doing too: looking at the data. Those data can tell us a lot more than the "expert" opinion of those who cannot or won't deal with the real evidence. Let's stop talking with the empty chair. The public deserves better.