Data for OECD countries document: 1. imports and exports are about three times as volatile as GDP; 2. imports and exports are pro-cyclical, and positively correlated with each other; 3. net exports are counter-cyclical. Standard models fail to replicate the behavior of imports and exports,...

This paper provides new evidence in support of the idea that bouts of optimism and pessimism drive much of US business cycles. In particular, we begin by using sign-restriction based identification schemes to isolate innovations in optimism or pessimism and we document the extent to which such...