<p>I would agree that one way to get an approximation of how many applications are truly unqualified is to look that the number rejected (rather than deferred) in the EA round.</p>
<p>However, as has been mentioned, this would not tell the whole story as there are plenty of perfectly qualified applicants who are not competitive at all.</p>
<p>This effect, as well as the effect of hooked applicants that has been mentioned before, is most influential only at the very top schools. Cornell, for instance, is not filling half of its class with hooked applicants the way Harvard may even though both are “highly selective” relative to the large majority of the colleges in country. As the ratio of applications to spots goes down, the different between a “qualified” and “competitive” applicants obviously decreases greatly. For a great many schools there may be no difference.</p>