During the Great Recession, teacher layoffs in Charlotte Mecklenburg Schools were not based solely on seniority. Instead, administrators targeted teachers who were retired, late-hired, unlicensed, low-performing, or nontenured. The study found that losing an effective teacher led to a greater decrease in math achievement compared to losing an ineffective teacher. Teacher seniority did not have a significant impact on the effects of layoffs. The district's approach resulted in selecting less effective teachers than those identified under a seniority-based policy, while also reducing job losses.