I don't doubt a Tiger mom of a reasonably intelligent child could get their kid into an Ivy by pushing like crazy.
That depends on the number of smart kids with Tiger moms compared to the number of Ivy League slots available.
According to the "2010 College-Bound Seniors Total Group
Profile Report"
http://professionals.collegeboard.com/profdownload/2010-total-group-profile-report-cbs.pdf on SAT scores, there were 71,160 students who earned scores of 700 and above on the SAT Critical Reading section and 104,334 who did so in Mathematics.
If there are about 20,000 spots in the freshman classes of the Ivies, lots of "reasonably intelligent" children are not getting in.
I think graduates of selective colleges are more successful on average than those of non-selective ones because of their intelligence and drive, rather than differences in the quality of education they receive at college, so the stakes in selective college admissions are lower than people think.
