U.S. President Barack Obama is set to deliver an address about the US Economy and income inequality (Photo: REUTERS/Yuri Gripas)


President Obama is scheduled to give a speech tomorrow in Illinois addressing the US economy. Home prices, stock prices, and retail sales have all rebounded since the depths of the recession in 2009. But unemployment remains stubbornly high. And the gap between rich and poor continues to widen, and remains high by international and historical standards.

When economists talk about income inequality, they like to refer to something called the Gini Index. It’s a number from zero to 100. If a society is perfectly equal, meaning if you, me, and the next guy have the exact same income, our Gini score would be zero.

If our society were perfectly unequal – everything for me, nothing for you – the number would be 100.

Michael Norton at the Harvard Business School — and author of the new book “Happy Money: The Science of Smarter Spending – studies how nations rank, and the falling US position drifting toward greater inequality.