Based on the notions of economic efficiency that I laid out here, if I could do whatever I wanted I would make the following changes over a ten-year period. (Some faster, some slower, some phased in, some implemented instantly on a given date.) The appropriate amounts in each case require a better calculator than I have access to.
Tax All Corporate Profits Like S-Corps, and Eradicate Taxes on Corporations, Dividends, and Capital Gains. Credit for the idea goes to Milton Friedman (Capitalism and Freedom, page 174 in my edition). Shareholders pay taxes on the year’s corporate profits (at normal earned-income rates or higher), whether or not they’re distributed. No more double taxation, but no more preferencing over earned and interest income, or indefinite/eternal deferral.
Eradicate Tax Deductions for Interest Payments — Personal and Corporate. Mortgage- and corporate-interest deductions are terribly distortionary; they encourage borrowing — debt financing — over equity- and self-financing. And they’re regressive.
Eradicate Business Deductions for Employee Health Care/Insurance. Destroy the distortionary historical artifact of employer-based health care coverage. Stop discouraging self-employment and personal choice of health-insurance options. (Having been self-employed for decades, I take this very personally. It’s cost me many tens of thousands of dollars.)
Scrap the Cap on Social Security Taxes. Include all earned income. This only makes a terribly regressive tax somewhat less regressive, and it expands the tax slice from that still-regressive tax — a tax that discourages working for a living because it only taxes earned income. But it makes Social Security cash-flow solvent beyond the foreseeable horizon (revenues support outlays). Other propositions here should be scaled to compensate for its regressiveness and work disincentive.
Change All Local Property Taxes to Land-Value-Only Taxes. Land value taxes are the least distortionary taxes around. This would remove the disincentive to improve land. Since it’s non-distortionary, it would also be good to increase its total share of the tax take.
Greatly Expand and Simplify the Earned Income Tax Credit, and Deliver it on Weekly Paychecks. Beyond its manifest benefits to tens of millions, and turbocharger effect on the economy, it could allow for some reduction or eradication of other (economically inefficient) means-tested payments.
Tax Carbon. Since people/businesses aren’t paying for their negative externalities, it’s distortionary not to tax carbon. All hail Arthur Pigou. This is a non-progressive tax, so other taxes would need adjustment to compensate.
Reduce Income Taxes and Make Them More Progressive. As possible and needed, given the other changes, to achieve:
1. Make the whole tax system — local, state, and federal combined — actually progressive. All the way from the bottom to the top.
2. Increase the total tax take by a few percentage points of GDP. Because Americans (notably, Tea Partiers) want the amount of government we’ve got. So they need to cover the costs. True conservatives pay their bills.
Cross-posted at Asymptosis.