for all you Apple fanatics... <a href="http://knowledge.wharton.upenn.edu/articlepdf/1903.pdf?CFID=1078516&CFTOKEN=45791179&jsessionid=9a30de94055073c3f3c4" target="_blank">http://knowledge.wharton.upenn.edu/articlepdf/1903.pdf?CFID=1078516&CFTOKEN=45791179&jsessionid=9a30de94055073c3f3c4</a>