<span> is an example of the free rider problem, because the programs benefit everyone and many listen but not everyone pays for it.</span>
Trade flourished because these progressing empires were developing new ways to produce products and utilize agriculture in their areas, such as Han with silk and Rome with olives and fishing/seafaring. These empires has never had access to goods that were from other areas before the Silk road, causing trade to become immensely popular and relied upon.
