US GDP Plunges 32.9 Percent in Worst Second Quarter Ever The percentage is the worst decline in U.S. history, eclipsing every major economic disaster, including the Great Depression. As steep as this decline was, economists had predicted a worse fall of 34.7 percent. The closest percentage drop of gross domestic product (GDP) occurred in the middle of 1921. Mark Zandi, Moody's Analytics, via CNBC The GDP was greatly affected by sharp declines in personal consumption, state and local spending, exports, investment and inventories. Personal consumption declined a whopping 25 percent. In addition, unemployment filings increased for a second straight week after showing signs of decline.