AbstractTo what extent do firms insulate their workers' wages from fluctuations in product markets? Which firm and worker attributes are associated with wage flexibility at the micro level? We first rely on Guiso, Pistaferri and Schivardi (2005) to estimate dynamic models of sales and wages, finding that in Portugal, workers' wages respond to permanent shocks on firm performance, as opposed to transitory shocks. We then explore the factors associated with wage flexibility, finding that collective bargaining and minimum wages are associated with higher wage insurance by the firm, while the threat of firm bankruptcy reduces it. Managers receive less protection against permanent shocks than other workers.