JUDGING from our "most commented" sidebar widget, our readers find debates about taxation riveting. "Give the people what they want!" could be the motto of capitalism and democracy both, so far be it from me to disappoint with a post not about taxes. But don't worry: I'll spare us all further discussion of the distribution of the tax burden, and instead take up the question of what a rational and fair tax policy might look like.

This subject might be less controversial than one thinks, judging from a recent Planet Money piece on six policies five economists ranging across the ideological spectrum all find agreeable. (I support all these policies, too, which I think must mean I'm an economist.) Of the six proposals, only one, marijuana legalisation, is not a tax policy. For now, let's set aside the proposals to eliminate the home-mortgage deduction, end corporate deductions for employee health-care costs, and tax carbon emissions, in order to focus on the remaining two:

Three: Eliminate the corporate income tax. Completely. If companies reinvest the money into their businesses, that's good. Don't tax companies in an effort to tax rich people. Four: Eliminate all income and payroll taxes. All of them. For everyone. Taxes discourage whatever you're taxing, but we like income, so why tax it? Payroll taxes discourage creating jobs. Not such a good idea. Instead, impose a consumption tax, designed to be progressive to protect lower-income households.

Yes! Why argue about income-tax rates if there ought not be an income tax at all?

Of course, if we did have a progressive consumption tax, we'd argue just as spiritedly about how progressive it ought to be. One sensible way to implement a consumption tax is to retain the basic structure of the status-quo income tax, but to treat all income saved or invested as tax-exempt. What is taxed is then, in effect, what is spent. If I had my druthers, all or most of the progressivity in this scheme would come from a graduated negative-income-tax element designed to guarantee all citizens a certain minimum income. Income (spent or saved) up to the minimum-income threshold would go untaxed, and incomes below the threshold would be supplemented with a government transfer. For those beyond the minimum income, I would prefer, on equity grounds, a single tax rate on all consumption. However, I think the distributive logic of democracy makes this extremely unlikely.

An ideal system which substituted the corporate income tax with a levy on carbon consumption, and took away the home-mortgage deduction, would almost certainly increase the overall tax burden of the middle class. In terms of policy, this is a feature not a bug; fiscal balance is fanciful unless the middle class shoulders a heavier burden than it does now. However, middle-income voters tend not to suffer taxation gladly, and politicians will always compete to court them with subsidies for middle-class things. Unsurprisingly, middle-class breaks often redound to the benefit of wealthy, well-connected interests. For example, land owners and construction companies benefit when government subsidies boost demand for home-ownership. Rather than see a beautiful, fair, flat consumption tax become a moth-eaten mess due to predictable public-choice dynamics, I'd prefer to see higher rates on consumption above certain thresholds from the outset. This sort of strategic progressivity cannot entirely forestall politicking give-aways to the middle class, but it may prevent some of it. By catering to widespread intuitions about distributive justice from the start, attempts to exploit those intuitions for ad hoc rent-seeking purposes may be less successful.

Regrettably, none of the "Planet Money" economists' tax proposals are presently on the table. One farseeing way to think about the contest between Mitt Romney and Barack Obama is to resist becoming too fixed on the argument between them on top tax rates, as fascinating as that debate might be, and concentrate instead on which candidate is more likely to move the whole American tax system toward the economists' consensus position. I reckon that Mr Romney would be more likely to have success in this regard, but mostly because I think Mr Obama is likely to continue to be mostly stymied by vehement opposition from congressional Republicans, no matter what it is he tries to do.