The Millionaire Next Door by Thomas J. Stanley and William D. Danko)

Most people with high incomes fail to accumulate any lasting wealth. They live hyperconsumer lifestyles, spending their money as fast as they earn it. In order to accumulate wealth, in order to become rich, one must not only earn a lot (play “good offense”, according to Stanley and Danko), but also develop frugal habits (play “good defense”).