I think the thing is that US has more sort of live in the moment culture. Most of the people there imagine a life where they would work for 5 days and spend that earned money on the weekend. Moreover as the culture in US is that people generally don't have to give a fortune of money to their offsprings as they think they should earn their. Life on their own. Moreover the government takes care of the retirement benefits to every person who is incapable of earning after a certain age so this I think is the reason why US ranks last on this list of average savings across the globe.