<p>Most top law and business schools don’t like to accept too many of their own undergrads. This is know as “inbreeding”.</p>
<p>However, there are numerous “gentleman’s agreements” to accept a certain number of undergrads from their competitors. Thus, if you were to look at Harvard Law School’s student make-up, about half of their class consists of Ivy League-class (plus Stanford, Duke, Northwestern, MIT, Michigan, etc.) undergrads. For example, HYP alone is probably 20-25% of Stanford Law School’s enrollment. So a giant state school like Illinois might have one undergrad admitted to Harvard every other year, while Yale has 20or so every year. Columbia undergrads fare quite well in this environment, too, although not the same as HYPS. Columbia Law School operates its admissions office similarly.</p>