Barry Eichengreen and Doug Irwin look at the drivers of Depression-era protectionism:
The Great Depression was marked by protectionist trade policies and the breakdown of the multilateral trading system. But contrary to the presumption that all countries scrambled to raise trade barriers, there was substantial cross-country variation in the movement to protectionism. Specifically, countries that remained on the gold standard resorted to tariffs, import quotas, and exchange controls to a greater extent than countries that went off gold. Just as the gold standard constraint on monetary policy is critical to understanding macroeconomic developments in this period, national policies toward the exchange rate help explain changes in trade policy. This suggests that trade protection in the 1930s was less an instance of special interest politics run amok than second-best macroeconomic policy management when monetary and fiscal policies were constrained.