Today is the 100th anniversary of the day President Woodrow Wilson signed the income tax into law.

I knew I felt kinda down for some reason.

Donald J. Boudreaux of Cafe Hayek asks “Did The Income Tax Lead To Prohibition?” –

 Prior to the creation in 1913 of the national income tax, about a third of Uncle Sam’s annual revenue came from liquor taxes. (The bulk of Uncle Sam’s revenues came from customs duties.) Not so after 1913. Especially after the income tax surprised politicians during World War I with its incredible ability to rake in tax revenue, the importance of liquor taxation fell precipitously.

By 1920, the income tax supplied two-thirds of Uncle Sam’s revenues and nine times more revenue than was then supplied by liquor taxes and customs duties combined. In research that I did with University of Michigan law professor Adam Pritchard, we found that bulging income-tax revenues made it possible for Congress finally to give in to the decades-old movement for alcohol prohibition.

Before the income tax, Congress effectively ignored such calls because to prohibit alcohol sales then would have hit Congress hard in the place it guards most zealously: its purse. But once a new and much more intoxicating source of revenue was discovered, the cost to politicians of pandering to the puritans and other anti-liquor lobbies dramatically fell.

Prohibition was launched.

Despite pleas throughout the 1920s by journalist H.L. Mencken and a tiny handful of other sensible people to end Prohibition, Congress gave no hint that it would repeal this folly. Prohibition appeared to be here to stay — until income-tax revenues nose-dived in the early 1930s.

From 1930 to 1931, income-tax revenues fell by 15 percent.

In 1932 they fell another 37 percent; 1932 income-tax revenues were 46 percent lower than just two years earlier. And by 1933 they were fully 60 percent lower than in 1930.

With no end of the Depression in sight, Washington got anxious for a substitute source of revenue.

That source was liquor sales.

We now have a top tax rate of 39.6 percent, and it’s actually much higher than that when you include the impact of other taxes, as well as the pervasive double taxation of saving and investment.

And the relatively simply tax law of 1913 has metastasized into 74,000 pages of Byzantine complexity.

Not to mention that the tax code has become one of the main sources of political corruption in Washington, impoverishing us while enriching the politicians, lobbyists, bureaucrats, and interest groups. Or the oppressive and dishonest IRS.

However, even though I take second place to nobody in my disdain for the income tax, the worst thing about that law is not the tax rates, the double taxation, or the complexity. The worst thing is that the income tax enabled the modern welfare state.

Before the income tax, politicians had no way to finance big government. Their only significant pre-1913 sources of revenue were tariffs and excise taxes, and they couldn’t raise those tax rates too high because of Laffer Curve effects (something that modern-day politicians sometimes still discover).

Once the income tax was adopted, though, it became a lot easier to finance subsidies, handouts, and redistribution.