Inventories have an important role in defining the business cycle and exert significant influence on perceptions of prosperity as measured by the national income accounts. As Chairman Bernanke noted in his recent testimony before Congress, inventories will be an important part of the near-term outlook for the U.S. economy.1 In the first quarter inventories fell by $103.7B, which subtracted 2.79 percentage points from real gross domestic product (GDP), almost half of the overall decline (Figure 1). Stockpiles have fallen by nearly $230B since the start of the recession—more than for any prior recession. The inventory decline remains significant even when looked at as a percentage of GDP (Figure 2). Over our forecast horizon we expect this decline in inventories to be the largest in the post-war era, in dollars as well as a percentage of GDP. While inventory levels will continue to contract, we estimate that in the second half of the year inventories will begin to add to GDP. The rebalancing of inventories and final sales defines the dynamics of the business cycle. Despite all the focus on the collapse of recently created financial instruments, the outline of the economic cycle follows the drive of inventories.