I don&#x27;t see any claim in the article that teacher quality matters more than student quality. It&#x27;s about interpreting teacher quality <i>relative to the quality of other teachers</i> as a dollar value.<p>There are two paragraphs, early on, that address or interestingly fail to address student quality. The first fails to address it:<p>&gt; The quality of the teachers in our schools is paramount: no other measured aspect of schools is nearly as important in determining student achievement. The initiatives we have emphasized in policy discussions—class-size reduction, curriculum revamping, reorganization of school schedule, investment in technology—all fall far short of the impact that good teachers can have in the classroom. Moreover, many of these interventions can be very costly.<p>Replacing the students with better students is an easy and effective way to see much larger gains in student achievement. It is not proposed as a policy reform for the obvious reason that it doesn&#x27;t do anything to help current students; it serves the needs of the school, not the students. (Imagine giving some parents who are trying to get their son to pass calculus the advice &quot;toss out your son and get a better one&quot;. This works if &quot;your son&quot; refers to &quot;whoever happens to be the son of this fixed couple, which may vary day-to-day&quot;, but not if &quot;your son&quot; itself refers to a fixed person.)<p>The following paragraph reports the range of teacher-to-teacher variation in quality (emphasis added):<p>&gt; Indeed, the magnitude of variation in the quality of teachers, even within each school, is startling. Teachers who work in a given school, <i>and therefore teach students with similar demographic characteristics</i>, can be responsible for increases in math and reading levels that range from a low of one-half year to a high of one and a half years of learning each academic year.<p>That clause I&#x27;ve emphasized is an admission that the impact of student quality is high enough to make measuring the effect of a teacher difficult.<p>Anyway, according to this article, the difference between getting the worst teacher at a school (-0.5 grade levels) and the best (+0.5 grade levels) is one grade level of achievement. Fifth graders differ among themselves by much more than five grade levels of achievement.<p>&gt; his claim, with evidence shown, is that teacher quality matters more [than student quality]<p>What evidence are you referring to? I see several estimates of the size of the impact of teacher quality, and not even a mention of the size of the impact of student quality.