Over the past two decades or so, a majority of states have implemented policies that link teenagers' driver's licenses to school attendance, academic performance, or behavior, but those requirements are not backed by solid research evidence. Experts trace the start of the trend to 1988, when West Virginia enacted a law linking driving privileges for teenagers under 18 to school attendance. It has evolved in recent years so that some states now include good academic standing as a criterion for getting or keeping a license as well. Twenty-seven states now have what is called "no-pass, no-drive" sanctions aimed at encouraging students to stay in school, behave well, and study. Some school counselors favor the common-sense approach, but researchers are skeptical, given that little more than anecdotal evidence is available on the issue. The problem with no-pass, no-drive policies is that they do not address the challenges that prevent students from attending school. Barring a youth from getting a driver's license does not help the student get adequate housing, develop strong social-emotional skills, get counseling, or receive tutoring support that may help him or her to succeed in school. One aspect of some of the no-pass, no-drive policies, however, that is grounded in research is that they may lead to increased monitoring of students by school staff members, which can produce early warnings that they are at risk of dropping out.