In the 1990s economic historians started talking about ?general-purpose technologies? as key factors driving long-term productivity growth. Key attributes of these gpts were held to include rapid improvement in the core technology, broad applicability across sectors and spillover?the stimulation of new innovations in associated products, services and business practices. Think printing presses, steam engines and electric motors. The new models? achievements have made ai look a lot more like a gpt than it used to.