This report provides early estimates on the effect of activation on Army and Air Force reservists' earnings. With caveats, these early estimates imply less prevalent and severe earnings losses than do estimates derived from DoD survey data. It also describes research using a sample of Army and Air Force reservists activated in 2001 and 2002 for the Global War on Terrorism. It estimates the effect of activation on reservist earnings. The results on earnings and activation reported in this document are early and subject to a number of important caveats, but the estimates do imply less prevalent and severe earnings losses among activated reservists than do estimates derived from DoD survey data.