Trade patterns and balances are influenced by unexpected events, not just economic models. Idiosyncratic shocks, like individual company issues, can greatly impact a country's overall economy. Traditional models assume these shocks balance out, but in reality, they can cause significant fluctuations. By analyzing trade data from 1970 to 1997, researchers found that current models can only explain half of the changes in trade volumes. This shows the importance of considering detailed data when studying a country's trade balance.