A second reason schools have become certification agencies is that this serves the interests of a society that wants people sorted and graded but does not know precisely what standards it wants to use. If high school diplomas or other certificates of competence were given solely for passing examinations, there would have to be political agreement on what the examinations should cover. This would be hard to get. Delegating the problem to the schools is a way of sweeping it under the rug.In many respects, the mantra of "education is the solution " is a way of passing the buck on social and economic problems.
Second, on page 137:
If credentials measured skills that were only learned in school, equalizing the distribution of schooling would equalize the value of the credentials schools conferred. But educational credentials also measure traits that people acquire outside of school. Equalizing the amount of kind of schooling that people receive cannot alter these traits. This means that an 8-year gap between the best- and worst-educated fifth today may be just as important as a 10-year gap used to be.Indeed, pushing more people through a system either requires Herculean efforts from the students, the educators, and the people around them, and vast resources for everyone involved, or certain polite fictions that were once called "Gentleman's C's." Graduation rates are hardly everything.