A small aside to your comment: GDP can be measured accurately, but sometimes it isn't. Some recent prominent examples are from Africa: http://www.theguardian.

A small aside to your comment: GDP can be measured accurately, but sometimes it isn't. Some recent prominent examples are from Africa: http://www.theguardian.com/business/2012/nov/20/economics-ghana http://www.theguardian.com/business/2012/nov/20/economics-gh...