<p>I always thought double spaced made it much easier to read. Single spaced, after reading thousands of essays, makes it easier for a reader to skip lines and lose place (atleast this is what I have seen trying to cram 3 chapters of a history reading into one night). Double spaced, IMO, is just easier to read. I doubt it matters in the end. It may be conventional to use single spaced, but noone will reject you for the line spaceing. An adcom told my school on a visit that she had seen essays with 6pt font and single spaced without margins to stress that our esssays need to be readable. If a college wants 1 page, single space it. If they do not specify anything besides word count, I would double space it to make it easier to read.</p>
<p>I was just about to ask this question too ;p</p>