Abstract
We study no-poach cartels using a wage-posting model that puts worker poaching at the center of labor market competition. Even when just two out of ten employers in a local labor market collude, wages fall by almost 5% market-wide. The reason is that no-poach agreements suppress competition along the job ladder, with spillovers to non-colluding firms. We then compare no-poach agreements to two other forms of anti-competitive conduct in the labor market: noncompete agreements and wage fixing. No-poach agreements have by far the largest negative wage effects.