This post originally ran on Robert Reich's website.

Why is there so little discussion about one of Bernie Sanders's

most important proposals – to tax financial speculation?

Buying and selling stocks and bonds in order to beat others who

are buying and selling stocks and bonds is a giant zero-sum game that wastes

countless resources, uses up the talents of some of the nation's best and

brightest, and subjects financial market to unnecessary risk.

High-speed traders who employ advanced technologies in order to get information

a millisecond before other traders get it don't make financial markets more

efficient. They make them more vulnerable to debacles like the "Flash

Crash" of May 2010.

Wall Street Insiders who trade on confidential information unavailable to

small investors don't improve the productivity of financial markets. They just

rig the game for themselves.

Bankers who trade in ever more complex derivatives – making bets

on bets – don't add real value. They only make the system more vulnerable to big

losses, as occurred in the financial crisis of 2008.

All of which makes Bernie Sanders's proposal for a speculation

tax right on the mark.

He wants to tax stock trades at a rate of 0.5 percent (a trade

of $1,000 would cost of $5), and bond trades at 0.1 percent.

The tax would reduce incentives for high-speed trading, insider

deal-making, and short-term financial betting. (Hillary Clinton also favors a

financial transactions tax but only on high-speed trading.)

Another big plus: Given the gargantuan size of the financial

market and the huge volume of trading occurring within it every day, this tiny

tax would generate lots of revenue.

Even a 0.01 percent transaction tax

(a basis point is one-hundredth of a percentage point, or 0.01 percent) would

raise $185 billion over 10 years, according to the nonpartisan Tax Policy Center.

Sanders's 0.5 percent tax could thereby finance public investments

that enlarge the economic pie rather than merely rearrange its slices – like

tuition-free public education.

After all, Americans pay sales taxes on all sorts of goods and

services yet Wall Street traders pay no sales taxes on the stocks and bonds

they buy.

Which helps explains why the financial industry generates about 30 percent of America's corporate profits but pays only about 18 percent of corporate taxes.

Naysayers led by the financial industry's lobbyists (the Financial Services Roundtable and

Financial Markets Association) warn that even a small tax on financial transactions would drive trading overseas, since financial trades can

easily be done anywhere.

Baloney. The U.K. has had a tax on stock trades for decades yet remains one

of the world's financial powerhouses. Incidentally, that tax raises about 3

billion pounds yearly (the equivalent of $30 billion in an economy the size of

the U.S.), which is pure gravy for Britain's budget.

At least 28 other countries also have such a tax, and the European Union is well on the way

to implementing one.

Industry lobbyists also claim the costs of the tax will burden small

investors such as retirees, business owners, and average savers.

Wrong again. The tax wouldn't be a burden if it reduces the volume

and frequency of trading – which is the whole point.

In fact, the tax is highly progressive. The Tax Policy Center estimates that 75 percent of it would be

paid by the richest fifth of taxpayers, and 40 percent by the top 1 percent.

It's hardly a radical idea.

Between 1914 and 1966, the United States itself taxed financial

transactions. During the Great Depression, John Maynard Keynes urged wider use

of such a tax to reduce excessive speculation by financial traders. After the Wall Street crash of October 1987, even the first

President George Bush endorsed the idea.

Americans are fed up with Wall Street's financial games.

Excessive speculation contributed to the near meltdown of 2008 – which cost

millions of people their jobs, savings, and homes.

So why is it only Bernie Sanders who's calling for a financial

transactions tax? Why aren't politicians of all stripes supporting it? And why

isn't it a major issue in the 2016 election?

Because a financial transactions tax directly threatens a major

source of Wall Street's revenue. And, if you hadn't noticed, the Street uses a

portion of its vast revenues to gain political clout.

So even though it's an excellent idea championed by a major candidate, a financial