Thursday, March 26 6:30 PM - 9:00 PM
Harney Science Center — 136 - Lecture Hall
Title: How People Use ChatGPT
Speaker: Zoë Hitzig, Junior Fellow at the Harvard Society of Fellows and former Research Scientist at OpenAI.
Abstract: Three years after its launch, ChatGPT was used at least weekly by ten percent of the global adult population. This paper documents several important facts about how people use ChatGPT using a large random sample of ChatGPT messages linked to demographic data via an automated privacy-preserving process. ChatGPT usage was initially higher among men and users from high-income countries, but those gaps had closed substantially as of September 2025. Although non-work usage has grown relatively faster, users on consumer plans still send hundreds of millions of work-related messages each day. Work-related ChatGPT usage is highly concentrated in knowledge-seeking activities like decision support and analyzing and interpreting information, regardless of user occupation. We develop a principal-agent model of AI chatbot usage that is motivated by evidence from people using ChatGPT both to ask for advice and to delegate tasks directly. The model highlights the central role of users’ demand for customization due to idiosyncratic preferences, which we call context. Using a novel classifier that measures conversational context, we find that users are more likely to ask AI chatbots for advice rather than work output when their queries have higher context requirements. Since context must be transmitted by the user, it may be a key bottleneck to unlocking economic value from AI.