Collaborating with AI Agents: Field Experiments on Teamwork, Productivity, and Performance

We examined the mechanisms underlying productivity and performance gains from AI agents using a large-scale experiment on Pairit, a platform we developed to study human-AI collaboration. We randomly assigned 2,234 participants to human-human and human-AI teams that produced 11,024 ads. We evaluated the ads using independent human ratings and a field experiment on X which garnered 5M impressions. We found human-AI teams produced 50% more ads per worker and higher text quality, while human-human teams produced higher image quality, suggesting a jagged frontier of AI agent capability. Human-AI teams also produced more homogeneous outputs (diversity collapse) as their ads were more self-similar. The field experiment revealed higher text quality (produced by human-AI teams) increased click-through rates and view time, while higher image quality (produced by human-human teams) improved cost-per-click rates. Two mechanisms explained these effects: Human-AI collaboration was significantly more task-oriented and displayed more delegation. AI-appropriate work processes, in turn, improved performance in human-AI teams and transcended the jagged frontier: Task-oriented communication produced higher productivity, higher quality ads across all dimensions, and displayed no diversity collapse in their outputs, while human-AI teams with more interpersonal communication were less productive and produced lower quality ads across all dimensions. In contrast, in human-human teams, interpersonal communication improved productivity. Delegation improved text quality in human-AI teams and was positively associated with diversity collapse, creating homogeneous outputs of higher average quality. The results suggest AI agents drive productivity, performance, and output diversity by reshaping teamwork along the jagged frontier of AI capabilities.