The U.S. is in a retirement crisis and our behavior is a key driver. Why do we tend to make poor choices? Academic research is beginning to help us better understand why.

1. People are financially illiterate since they lack understanding of
   simple economic concepts and cannot carry out computations such as computing compound interest, which could cause them to make suboptimal financial decisions.
2. Impatience or present-bias might explain suboptimal financial decisions. That is, some people persistently choose immediate gratification instead of taking advantage of larger long-term payoffs

This is according to a study published by Dr. Justine Hastings, Dr. Olivia Mitchell, and the Michigan Retirement Research Center at the University of Michigan:
How Financial Literacy and Impatience Shape Retirement Wealth and Investment Behaviors (download here).