mobility and aging,”Almost one-fifth of the U.S. population and two-fifths of Canada’spopulation relocate. Urbanization is a powerful force behind thismobility. In fact, some cities such as Vancouver, Toronto, Atlanta,and Washington
DC have satellite cities on their peripheries that hostbusinesses dealing in technology and international trade. The number of older North Americans grew rapidly in the twentiethcentury. This is because of an increase in life expectancy and adecrease in birth rates.”