It's actually very widespread in all sorts of countries and cultures. There was a good Planet Money show that talked about it here: http://www.npr.org/blogs/money/2013/06/18/193176928/episode-...…
It's actually very widespread in all sorts of countries and cultures. There was a good Planet Money show that talked about it here: http://www.npr.org/blogs/money/2013/06/18/193176928/episode-...…