I hear it became harder for horses pulling buggies on city streets after the invention of the automobile. In general, there is always competition among new and old forms of technology, and there is always competition among business enterprises. A good book to read about the subject (which goes back before the invention of the automobile) is<p><a href="http://www.econlib.org/library/Smith/smWN.html" rel="nofollow">http://www.econlib.org/library/Smith/smWN.html</a><p>Note that this is FREE and in the public domain. There are other online postings of the book.