CONCEPT
Complementarity and Substitution
The economic distinction — central to Autor's AI analysis — between technologies that replace human labor in specific tasks and those that enhance human productivity, determining whether wages rise or fall as a given technology diffuses.
The complementarity/substitution distinction is the analytical engine that connects Autor's task-based framework to wage outcomes. A technology substitutes for labor when it performs tasks workers previously performed, reducing demand for those workers. A technology complements labor when it increases the productivity of tasks workers continue to perform, raising their marginal product and therefore their wages. Most technologies do both simultaneously, and the net effect on any worker depends on the balance: whether the substitution of AI for some of her tasks is offset by the complementarity of AI with her remaining tasks. This balance is not fixed by the technology; it depends on how work is designed, which skills workers bring, and which tasks AI is deployed to perform. The distinction reframes the AI debate from a binary 'will AI take jobs?' into the more precise question: which workers will find AI substituting for them and which will find it complementing them?
