Understanding large economic downturns is one of macroeconomics’ central goals. This column argues that imbalances in input-output linkages can interact with firm-level shocks to produce output fluctuations that are much larger than the underlying shocks. The result can be large cycles arising from small, firm-level shocks. It is thus important to study the determinants of large economic downturns separately. Macroeconomic tail risks may vary significantly even across economies that exhibit otherwise identical behaviour for moderate deviations.