On a spring night in 1983, a chemist employed by the Cetus Corporation had a wonderful insight. While working on a narrow problem, Kary Mullis stumbled onto the principles of the polymerase chain reaction (PCR). The story behind this discovery is exciting because the stakes involved turned out to be so high. Mullis won a Nobel Prize. Molecular biologists were given a powerful research tool. Doctors got new diagnostic tests. Police investigators could begin to lift DNA “fingerprints” from small and badly degraded biological samples. Discoveries this dramatic are rare, but the underlying elements in the story have broad relevance. They illustrate an important aspect of economic activity that often goes unnoticed in discussions of what it is that managers do.