When the 2001 tax bill passed, I noted its repeal of the estate tax repeal would last “only for one year (2010). In that same year, assets would begin to be inherited at their purchase price rather than market value (carryover basis), so heirs would inherit old capital-gains tax liabilities. … If carryover basis were maintained after 2010 … then heirs could end up brutally taxed on both the value of inherited assets and old gains on those assets.”

A Wall Street Journal fact-checker called, thinking I must have made a mistake. But Congress made the mistake and now has to fix it. There are not enough Senate votes for repeal, so the debate is down to choosing between a 45–55 percent tax rate with a hypothetical $10 million exemption or Republican Sen. Jon Kyl’s plan of a 15 percent tax rate with a $3.5 million exemption.

The Washington Post’s writers Jeff Birnbaum and Jonathan Weisman spin this too much, putting economics aside and depicting it as only a contest between the very wealthy (who would pay zero estate tax with a huge exemption), and the extremely wealthy (some of whom might pay less with a lower rate, despite the smaller loophole). But they did note the estate-planning industry is lobbying hard against a 15 percent estate tax, which would kill its costly tax-avoidance schemes.

For the few who might put economics before politics, this is no contest. Combining huge loopholes with high marginal tax rates is the textbook definition of a foolish tax — one that maximizes economic distortions while minimizing revenue.

Meanwhile, as I warned in 2001, New York Times writer Edmund Andrews pretends it is a “strange wrinkle” that Mr. Kyl would not combine carryover basis with the estate tax. This has never been done because it would tax both the entire value of inherited assets plus any past gains on the same assets.

Mr. Birnbaum and Mr. Weisman cite the “nonpartisan” Tax Policy Center, three members of which (Len Burman, Bill Gale and Jeff Rohaly) recently argued: “Repeal would be expensive. … Making repeal permanent as of 2010 would cost $270 billion in the next 10 years. Repeal would also be regressive [and] would reduce charitable giving by more than $15 billion a year.”

On the first point, the alleged revenue loss from scrapping the estate tax — $27 billion a year after 2010 — would be only seven thousandths (.007) of total revenue, estimated at $3.8 trillion in the middle of that ten year span (2015). Alicia Munnell, an economist with the Clinton Treasury, estimated the cost of collecting the estate tax is as large as the revenue collected.

These trivial estimates of revenues lost by scrapping the estate tax are static — they “do not account for behavioral response.” Yet we must consider the effect of the estate tax planning on: (1) income tax receipts, and (2) investment and entrepreneurship.

In 1987, a study in Tax Policy and the Economy by Douglas Bernheim of Stanford concluded “available evidence suggests that, historically, true revenues associated with estate taxation may well have been near zero, or even negative.”

The estate tax lowers income taxes through such devices such as giving stocks and bonds to heirs in lower tax brackets, funding M.D. degrees for grandchildren, deducting tax-avoiding life insurance premiums from business income and setting up tax-exempt foundations.

Supply-side effects make it even less likely the estate tax will raise revenue. As a July Congressional Budget Office (CBO) study notes, an estate tax can “lead people to invest less than they would otherwise” and “reduce entrepreneurial efforts.”

Any claim repealing the estate tax would be “regressive” assumes the tax is harmless. On the contrary, as Joseph Stiglitz explained in “Notes on the Estate Tax” in 1978, “reductions in savings and capital accumulation will, in the long run, lead to a lower capital-labor ratio; and the lower capital-labor ratio will… lead to an increase in the share of capital. Since income from capital is more unequally distributed than is labor income, the increase in the proportion of income accruing to capital may increase the total inequality of income.”

Messrs. Gale, Burman and Rohaly imagine total repeal of the estate tax would have a “devastating” effect on charitable giving. They cite an unofficial paper by CBO economists who sought a diplomatic compromise between conflicting estimates by Mr. Gale and a Treasury economist, concluding an estate tax of zero might have trimmed charitable giving by $14 billion (it was $249 billion in 2004).

In a 1997 study for the Philanthropy Roundtable, “Death, Taxes and the Independent Sector,” I noted charitable giving rose by a record 28 percent in real terms from 1982 to 1989, after the highest tax rate was cut from 70 percent to 28 percent on income and from 70 percent to 50 percent on estates.

In fact, charitable giving has long been a surprisingly constant share of income, whether tax rates rose or fell. Giving was 2.3 percent of gross domestic product in 1973, when the top income tax was 70 percent; 2.3 percent in 1989, when the top tax was 28 percent; and 2.3 percent in 2003, when the top tax was 35 percent.

I also found, however, that differences between tax rates on income, estates and capital gains did indeed affect the timing and form of charitable contributions. Income tax rates were much lower than estate tax rates after 1986, and that wider gap reduced the relative value of charitable tax deductions for giving during life, compared with tax advantages of bequests and foundations after death.

The increased capital gains tax from 1987 to 1996 also discouraged asset sales before death, further delaying the timing of charitable giving. The 1986 alternative minimum tax on gifts of appreciated property (except to foundations) further favored foundations over charities.

“In addition to altering the timing and form of charitable contributions,” I wrote in Philanthropy, “estate taxes affect work and saving habits in ways that have important consequences for income and, as a consequence, for philanthropy. The estate tax discourages the accumulation of assets beyond the exempt amount. This makes capital more scarce than otherwise, slowing the growth of productivity and real wages. Reducing or eliminating the death tax, accordingly, would provide greater incentives to accumulate larger estates. The result would be a larger national capital stock and a larger future flow of capital income to be used for all purposes — including charities.”

All the self-interested and ideological efforts to rationalize high tax rates on estates are as indefensible as were similar efforts to rationalize higher tax rates on dividends. Because we have a tax on capital gains, it makes sense to impose the same tax rate on estates to avoid distorting the timing of asset sales.

Any estate tax higher than the capital gains tax is socially counterproductive, hurting the economy and overall tax receipts, while benefiting nobody except estate-tax planners.