as life expectancy rises and birth rates decline in developed countries, the median age rises accordingly. according to the united nations, this process is taking place in nearly every country in the world. a rising median age can have significant social and economic implications, as the workforce gets progressively older and the number of old workers and retirees grows relative to the number of young workers. older people generally incur more health-related costs than do younger people in the workplace and can also cost more in worker's compensation and pension liabilities. in most developed countries an older workforce is somewhat inevitable. in the united states for instance, the bureau of labor statistics estimates that one in four american workers will be 55 or older by 2020.