The NAS figures could take on added significance at a time when the government is touting an overhaul of Medicare and Social Security as its best hope for reducing the ballooning federal debt.

• 当政府正在鼓吹检查医疗保险和社会保障这一时刻，国家科学院的数字可能具有额外的意义，因为政府最期望减低不断膨胀的联邦债务负担。