<p>You will NOT have a lower chance of acceptance through ED. That makes absolutely no sense from the college’s perspective–even if it’s your second choice, you are still a lock yield-wise. Whether ED (either round) provides increased chance of acceptance is controversial, but regardless, it benefits the college more than it benefits the student.</p>
<p>Financial aid is the usual deterrent. If your family’s finances are simple, I encourage you to try both Amherst’s and Williams’s free online FA calculators. Each school’s institutional methodology is different, but none of them like to vary too much from their closest peers. (Note: The previous sentence is entirely inapplicable if your finances are not simple.)</p>