Your analysis sounds likely. Perhaps its more pronounced at the local level than at the Ivies. I heard of one study that said legacy doesn't increase donation. At the college level. Note also that MIT and Cal Tech don't do legacy. I think Harvard and Stanford are up front about, endow a chair ($3mm?), get your kid in.
But local prep schools might actually need those endowment donations. Not having $20 - 40 billion to kick around. They'll be more enmeshed with local politics.
I think the big intake years are generally K, 6, 9.
