# Method in Action: US Prohibition (1920–1933)

> *This example is part of the [second-order-thinking](../SKILL.md) skill.*

A worked example of the cascade — the kind that ends in a constitutional repeal. Not a victory parade.

In January 1920, the **Eighteenth Amendment** to the U.S. Constitution prohibited the manufacture, sale, and transport of intoxicating liquors. The first-order intent was straightforward: reduce alcohol consumption and the social ills attributed to it (domestic violence, workplace accidents, public drunkenness).

The first-order effect did appear: per-capita legal alcohol consumption dropped sharply in the first year. First-order thinking — the consensus prediction at the time — was correct, in isolation.

**Second-order:** outlawing legal supply did not extinguish demand; it transferred supply to illegal channels. Bootlegging, smuggling, and home distilling expanded immediately. The supply curve shifted from legal-regulated to illegal-unregulated.

**Third-order:** meeting that demand required infrastructure for illegal production, distribution, and protection. **Organized crime** scaled to fill the gap — Al Capone's Chicago Outfit, the Genovese family, and others — building national networks where small criminal enterprises had existed before.

**Fourth-order:** violent territorial rivalries among criminal organizations; widespread corruption of police, judges, and federal Prohibition agents; weakened public trust in the rule of law; and dangerous adulterated liquor — the federal government deliberately denatured industrial alcohol, causing an estimated 10,000+ fatalities by 1933.

**Fifth-order:** in February 1933, the **Twenty-First Amendment** was proposed; by December it had been ratified. It repealed the Eighteenth — the only constitutional amendment ever repealed by another. The goal of "reducing the social ills of alcohol" was not achieved; alcohol consumption merely shifted from regulated to unregulated, with substantial collateral damage.

**The reversal:** the policy's first-order effect (reduce legal alcohol → reduce harm) was reversed at orders 3–4 by the system's response (illegal supply → organized crime → systemic harm exceeding the original problem). All affected groups suffered: the target group (drinkers, who got dangerous liquor instead of safe), bystander groups (police, courts, public-health), and groups the policy did not imagine it would touch (immigrant communities scapegoated, federal-state relations destabilized).

This is the canonical case of a policy whose **immediate effect was correctly predicted** and whose **equilibrium effect was the opposite of the intent**. The fallacy was tracing only the first-order effect on the target group and stopping — exactly what Hazlitt named.

**Sources:** Eighteenth Amendment (1919) and Twenty-First Amendment (1933), U.S. National Archives: https://www.archives.gov/founding-docs/amendments-11-27 ; Okrent, Daniel. *Last Call: The Rise and Fall of Prohibition* (Scribner, 2010); Blum, Deborah. *The Poisoner's Handbook* (Penguin Press, 2010) on the federal industrial-alcohol denaturing campaign.