The United States has been shaped by its experience with mass immigration. According to the United Nations, 14% of the US population are immigrants, more than four times any other country. According to the International Labour Organization, Americans typically work 10 more weeks each year than their European counterparts. As the world’s largest economy, the US economy is distinct from other advanced economies in that it has limited central government intervention in favour of a free market, private enterprise system. The US labour movement is still divided between industrial and craft unions. And US companies do not typically use employer organisations to advance their interests in dealing with workers.