6 ideas
A stable international economy needs one actor to do five things: keep its market open to distressed goods, supply countercyclical long-term lending, maintain a relatively stable exchange-rate system, coordinate macroeconomic policies, and act as lender of last resort by discounting in financial crises. When no country performs these functions, shocks that would otherwise be absorbed spread and deepen across borders.
The Depression was so wide, so deep and so long because no country acted as stabiliser. Britain could no longer carry the role and the United States would not take it up, so the system had no one to keep markets open, keep lending, or discount in a panic. The collapse came from this gap in leadership during a handover of power, more than from any single policy error or monetary mechanism.
A stabiliser should lend abroad when the world economy weakens. In 1928–29, US foreign lending did the opposite: it stopped suddenly as capital was pulled into the Wall Street boom, then was withdrawn further as the slump began. Debtor countries lost financing just when their export earnings fell, which forced deflation and default and spread the downturn.
In 1931, Austria's Creditanstalt failed, and the rescue loans that followed were too small, too late, and tied to political conditions, including French objections to an Austro-German customs union. The panic spread to Germany and then to sterling, forcing Britain off gold in September 1931. The case shows how a lender of last resort that haggles instead of discounting freely turns a local bank failure into a systemic run.
Falling prices for primary commodities spread the Depression by cutting the export earnings and debt-service capacity of agricultural and raw-material producers. Those producers then cut their imports and defaulted, which fed back on the industrial countries. Viewed this way, a price decline is a structural shock that transfers distress between regions rather than a benign adjustment.
When the largest economy raised tariffs, most visibly with Smoot-Hawley in 1930, instead of keeping its market open to distressed goods, other countries retaliated with tariffs, quotas, exchange controls and competitive devaluations. Each country acted rationally to protect itself, but together these actions shrank world trade in a downward spiral. Only a dominant power willing to absorb surpluses can stop that collective-action trap.