Urban schools are often tempted to impose school uniforms on the presumption that this resolves some discipline problems linked to clothing and gangs. The counterpart of this supposed benefit is that those uniforms are costly. Thus, the improvement in discipline better be worth it, including indirect effects on student performance.
Scott Imberman and Elisabetta Gentile look at a school district where some schools have adopted uniforms. And it turns out the gains are minimal: none in elementary school, and only slight improvements in attendance and language skills in higher grades. And these small positive impacts are limited to female students. Is this worth the cost of the uniforms? I do not think so.