A central decision faced by firms is whether to make intermediate components internally or to buy them from specialized producers. We argue that firms producing products for which rapid technological change is characteristic will benefit from outsourcing to avoid the risk of not recouping their sunk cost investments when new production technologies appear. This risk is exacerbated when firms produce for low volume internal use, and is mitigated for those firms which sell to larger markets. Hence, products characterized by higher rates of technological change will be more likely to be produced by mass specialized firms to which other firms outsource production. Using a 1990–2002 panel dataset on Spanish firms and an exogenous proxy for technological change, we provide causal evidence that technological change increases the likelihood of outsourcing.