This book examines economic measurement in light of lessons learned in the financial crisis. One set of papers investigates how gaps in the data contributed to our failure to spot emerging risks to financial stability before and during the crisis. These papers describe strategies for filling these gaps and for coping with the inherent dynamism of the financial marketplace. Another set of papers discusses recent changes in measuring financial activity in the areas of defined benefit pension plans and cross border investment income. These change the picture of saving by sectors, particularly households and state and local governments, and help explain some anomalies in net investment income receipts of the US. Other papers use micro data to investigate the effects of the crisis on households and nonfinancial businesses. They find that a third of households suffered financial distress during the crisis, but experiences varied greatly, and a sizeable minority experienced gains in wealth. The high variance of outcomes may have affected aggregate spending because households reported they would respond more strongly to losses in the value of their assets than to gains. Also increases in personal saving can be traced to changes in households’ borrowing, not increased contributions to savings and retirement accounts. Finally, nonfinancial businesses were strongly affected by a loss of access to external sources of funding for their liquidity and investment needs. The empirical results suggest that policies that increase access to credit might be more effective in ending the recession than policies aimed at stimulating demand.