How do average hours worked vary across the world income distribution? To answer this
question, we build a new internationally comparable database of hours worked covering countries
of all income levels. We document that average hours worked per adult are substantially
higher in low-income countries than in high-income countries. This pattern is shaped by differences
along both the extensive margin (employment rates) and intensive margin (hours per
employed), with the former being quantitatively more important than the latter. Two important
implications of our findings are that both labor productivity and welfare differences across
poor and rich countries are substantially larger than suggested by GDP-per-capita differences.