如何纠正经济数据与现实的偏差

It is faintly surprising that one of the liveliest areas of economics these days is the question of measurement, and what relation published Statistics bear to what is happening in the economy. Statistics do not usually inspire excitement.

如何衡量经济活动以及统计数据与实际经济情况之间的关系最近成为了经济学最活跃的领域之一，这有点出人意料，统计学通常不会激起人们的兴奋之情。

This attention reflects the convergence of two strands of scepticism about the existing statistics, and in particular gross domestic product. One is the “productivity puzzle” and to what extent the mis-measurement of digital phenomena helps explain the slow rate of productivity growth. The other is the longstanding critique of GDP as a meaningful measure of progress, for reasons of environmental sustainability or other contributors to society’s wellbeing.

这种关注反映出对当前统计手段的两种质疑的共同点，尤其是针对国内生产总值(GDP)的质疑。一种涉及“生产效率谜题”，以及对数字经济的不当衡量在多大程度上有助于解释生产率增长缓慢。另一种是长期以来对GDP作为进步衡量指标的合理性的批评，理由是GDP未能考虑环境可持续性或者其他促进社会福祉的因素。

The two converge on the distinction between the aggregate amount of marketed economic activity and total economic welfare. The conventional statement about GDP is that it is only meant to count the former, not the latter. GDP does not capture environmental factors or consider income distribution. But as long as that gap has been roughly constant, GDP growth has been a good enough measure of improvement in economic welfare.

这两种怀疑都着眼于市场经济活动总量(marketed economic activity)和总经济福祉(total economic welfare)之间的区别。关于GDP，传统的说法是GDP只是为了衡量前者，而非后者。GDP并不把环境因素或者收入分配纳入考虑。但只要两者差距大致保持稳定，GDP增长率足以作为衡量经济福祉改善程度的良好指标。

Perhaps the wedge between total marketed economic activity and welfare is increasing because of the pace of technological change, but statistics have never captured the human gains from advances in periods of innovation, whether in medicines or the internet.

市场经济活动总量和总经济福祉之间的差距或许正因为技术变革而扩大，但统计从未考虑药物或者互联网等创新给人类带来的福祉。

This case for the defence of GDP is fundamentally weak, however. It in fact includes many non-marketed activities, yet excludes other productive activity. Business and government count as “the economy” but voluntary and household activities do not.

然而，这个为GDP辩护的理由根本站不住脚。GDP实际上涵盖了许多非市场的活动，却把其他一些生产活动排除在外。企业和政府都算作“经济”，但志愿劳动和家务劳动却不算在内。

Postwar social changes — a rising proportion of women working outside the home, and the increased purchases of prepared foods, professional childcare, domestic appliances and so on — have flattered the official productivity statistics for decades.

数十年来，战后的种种社会变化——走出家门工作的女性的比例上升，人们购买更多的预制食品、专业的儿童保育服务、家用电器等产品和服务——使官方的生产率数据被高估。

More subtly, the statistics blur the distinction between marketed economic activity and increases in economic welfare that cannot be priced by converting nominal GDP into “real” terms.

更微妙的是，通过把名义GDP转换为“实际”GDP，统计模糊了市场经济活动和无法定价的经济福祉增长之间的差异。

Economists and statisticians are beginning to accept that our framework for economic statistics needs to change. Some argue for developing better “satellite” accounts, where all the interesting data about the environment or the household are collated.

经济学家和统计学家开始接受，我们的经济统计框架需要改革。一些人主张设立更好的“卫星账户”，将一切有关环境或者家庭的有趣数据归入这个账户。

But why should all the pressing questions be satellites?

但为什么这些迫切的问题要居于附属地位呢？

GDP could certainly be improved. In one of the joint winners of the Indigo Prize essay competition, a team led by Carol Corrado and Jonathan Haskel, proposed better measurement of services and intangibles, and direct measurement of the economic welfare being created by digital goods. The other winning essay — which I co-authored with Benjamin Mitra-Kahn — proposed similar incremental changes as an interim step.

我们当然能够改进GDP。经济学奖Indigo Prize征文比赛的获奖者之一、由卡萝尔?科拉多(Carol Corrado)乔纳森?哈斯克尔(Jonathan Haskel)领导的小组，提出了更好地衡量服务和无形资产的方法，以及直接衡量数字产品创造的经济福祉的方法。另外一篇获奖文章——由我与本杰明?米特拉-卡恩(Benjamin Mitra-Kahn)合作撰写——提出了类似的渐进变革作为一种临时措施。

We opted for better measurement of intangibles, adjusting for the distribution of income, and removing unproductive financial activity. The long-term recommendation was more radical: ditching GDP as the metric of progress in favour of measures of access to different kinds of assets, including financial wealth but also natural capital, intangible assets, infrastructure and human and social capital.

我们主张更好地衡量无形资产、根据收入分配进行调整，以及去除非生产性金融活动。针对长期的建议则更加激进：摒弃GDP作为衡量进步的指标，转而衡量人们获得和使用各类资产的机会，这些资产不仅包括金融财富，也包括自然资本、无形资产、基础设施、人力和社会资本。

This was inspired by Amartya Sen’s idea that prosperity consists in people having the capabilities needed to lead the life they would find meaningful; and by the need to get away from measuring economic progress only through the short-term flow of activity. There is no sustainability without a balance sheet.

这受到了两方面的启发，一是阿玛蒂亚?森(Amartya Sen)的观点，他认为繁荣的意义在于人们拥有过上自己认为有意义的生活所需要的能力；第二是我们有必要摒弃只通过短期活动情况来衡量经济进步的做法。没有一个“资产负债表”，就谈不上什么可持续性。

Perhaps neither the incremental nor the radical is the right approach. Reform will take time because there needs to be consensus about how to change; statistical standards are like technical standards. But I am now confident that in another 10 or 20 years GDP will have been dethroned.

或许上述渐进改革和激进改革都不是正确的策略。改革需要时间，因为需要就如何改革达成共识；统计标准就像是技术标准。但我现在确信，再过10至20年，GDP将走下神坛。