News Summary

• We measure how artificial intelligence (AI) affects the economy through its impact on software engineering productivity.
• We estimate the sensitivity of each firm’s stock return to an AI stock market index, and how this sensitivity depends on the share of firm payroll in software engineering.
• By mid-2026, amid rapid progress in coding agents, the effect of AI on productivity and GDP had more than doubled relative to the end of 2025.
• This is also a simple way of showing that markets do indeed price in the effects of AI.