Task Substitution and Uplift
Summary
Cunningham and Whitfill distinguish AI speedups on the tasks people performed before AI, speedups on the tasks they choose after adopting AI, and the resulting increase in value. Because people reallocate their time toward activities AI makes cheaper, these three measures can differ substantially even when they describe the same worker.
Why it matters
The framework explains why large speedups on selected AI-assisted tasks do not translate mechanically into equally large gains in worker productivity or economic value.
What to keep in mind
The ordering of the measures relies on simplifying assumptions about optimizing behavior and accurate beliefs. Observed AI tasks are also selected precisely because AI performs well on them.