Global sourcing and firm selection

•We present novel firm-level empirical evidence on global sourcing behavior.•We identify firms' self-selection into vertical integration and offshoring.•Firms that are more productive ex ante tend to select vertical integration.•Firms that are more productive ex ante tend to select offshoring.

We analyze the sourcing strategies of firms active in the Spanish manufacturing sector. We show that firms that select strategies of vertical integration and of foreign sourcing ex post tend to have been more productive, ex ante, than other firms.