I'd go even further and suggest that you wear a full suit. When I was interviewing for consulting jobs via phone from Ghana, I always wore a suit--even though they couldn't see me! Wearing the formal attire put me in an interviewing state of mind. Furthermore, with Skype, you may have to get up and move for some reason and end up showing them your "business on the top / party on the bottom" outfit, which would be a little awkward.
Wear a full suit or a full business casual outfit just like you're interviewing in person.
Good luck with your interview!
Kaneisha
Harvard Business School MBA 2010, Harvard Kennedy School MPA 2010
Founder, The Art of Applying
Admissions Consulting for MBA, MPP, Joint Degrees, and Fellowships
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