At the dawn of the 21st century our income tax system is 90 years old; Social Security and employer-provided health care and pension systems are over 60. These systems worked well in the thrilling days of yesteryear, but over the past half century families and the workforce have changed. Two-career families are common, and 70% of all married women are in the work force. Part-time work, especially by women, is commonplace, people change jobs frequently, and most single mothers work.