死亡率模式保持不变 何必为长寿烦恼

In developed countries today life expectancy at birth is about 80 years. That figure has almost doubled over the past century. Life expectancy at birth measures how long someone born today would survive if the patterns of mortality existing when they were born continued through their lifetime. But they will not.
在发达国家，现在出生的人预期寿命约为80岁。这个数字在过去的1个世纪里几乎翻了一番。人在出生时的预期寿命衡量的是，现在出生的人，如果他们出生时整个社会的死亡率模式在他们一生中保持不变，那么他们的寿命是多久。但死亡率模式不会保持不变。

These patterns improve, so that most people born in the past century have lived far beyond their life expectancy at birth. Children born today can expect to live well beyond 80 years, even if the claim by Peter Thiel and Aubrey de Grey that the first 1,000-year man is already alive is optimistic.
死亡率模式在不断改善，因此，过去一个世纪中出生的大部分人活着的时间，已经远远超出了他们出生时的预期寿命。即便企业家彼得•蒂尔(Peter Thiel)和学者奥布里•德格雷(Aubrey de Grey)宣称第1个能活到1000岁的人已经出现的说法过于乐观，但可以预计，今天出生的儿童的寿命将远不止80岁。

Life expectancy was much lower a century ago because many children died in infancy and many adults failed to achieve a normal lifespan because they were killed by now-curable infectious diseases. Deaths from these sources are now so low that even dramatic further improvements will not have much effect on average lifespan. The most important factor today is increases in life expectancy after conventional ages of retirement. This measure has recently been improving at one to two months a year.
一个世纪以前，预期寿命比现在低得多，因为当时婴儿夭折率很高，许多现在我们已经能够治愈的传染性疾病又提前夺去了许多成年人的生命。现在因这些原因死亡的人数很少，以至于即使在这方面出现巨大的进步，也不会显著提高平均寿命。如今最重要的因素是，预期寿命减去通常退休年龄后所余时间的增长。近年来这项指标每年提高1到2个月。

Life-saving advances are the greatest benefit of technological change. And yet when pundits discuss the future, the excitement around driverless cars and nanotechnology gives way to long faces when the topic moves to human longevity. It may be nice to live longer, but what about the effect on the economy? The question is absurd. Economic growth is about giving people more choices, and no choice is more earnestly sought than the chance of a longer life. The hard economic evidence is the amount that people are willing to pay to extend their lives even for short periods.
技术变革带来的最大福祉就是生命救助方面的技术进步。然而同样是在展望未来，专家们谈论起无人驾驶汽车和纳米技术时一脸兴奋，话题转到人类长寿时他们却拉长了脸。长寿固然好，但是这对经济的影响该怎么办呢？这个问题是荒谬的。经济增长的目的是给人们更多选择，而没有什么选择能比有机会延年益寿更让人魂牵梦绕了。为了延长寿命，哪怕只是很短的时间，人们也愿意花很多钱，这就是经济上的铁证。