Humans are social animals. Is the desire for attention from other people a quantitatively important non-monetary incentive? I consider this question in the context of social media, where
platforms like Reddit and TikTok successfully attract a large volume of user-generated content
without offering financial incentives to most users. Using data on two billion Reddit posts and
a new sample of TikTok posts, I estimate the elasticity of content production with respect to
attention, as measured by the number of likes and comments that a post receives. I isolate
plausibly exogenous variation in attention by studying posts that go viral. After going viral,
producers more than double their rate of content production for a month. I complement these
reduced form estimates with a large-scale field experiment on Reddit. I randomly allocate attention by adding comments to posts. I use generative AI to produce responsive comments in real
time, and distribute these comments via a network of bots. Adding comments increases production, though treatment efficacy depends on comment quality. Across empirical approaches, the
attention labor supply curve is concave: producers value initial units of attention highly, but
the marginal value of attention rapidly diminishes. Motivated by this fact, I propose a model of
a social media platform which manages a two-sided market composed of content producers and
consumers. The key trade-off is that consumers dislike low-quality content, but including lowquality content provides attention to producers, which boosts the supply of high-quality content
in equilibrium. If the attention labor supply curve is sufficiently concave, then the platform
includes some low-quality content, though a social planner would include even more.