第160周 | 经济学人外刊泛读

外刊原文&译文
In the absence of new ideas, growth must eventually grind to a halt. The adding of labour or resources or capital (machinery and such) to an economy can boost income, but with diminishing returns; in the absence of technological progress, ore becomes harder and costlier to mine and there are ever fewer valuable tasks to be done by an extra worker or industrial robot. New ideas, though, allow an economy to do more with less or create new and valuable tasks to occupy labour and capital. Technological progress has thus enabled steady growth in real income per person over the past two centuries even as global population has soared.

缺乏新想法，增长终将停滞。为一个经济体增添劳动力、资源或资本(如机械等)能够提升收入，但是收益递减；没有技术进步，矿石开采会更困难，成本也更高，能交给新增加的工人或工业机器人去做的有价值的任务越来越少。而新想法可以让一个经济体提升效率，或是创造有价值的新任务，让劳动力和资本能尽其效用。因此，过去两百年里全球人口飙升的同时，技术进步令人均实际收入稳定增长。

But new ideas must themselves be produced. An economy can increase the flow of ideas by adjusting its use of human resources: by investing more in education and encouraging more people to work in research rather than production, for instance. But while these solutions sufficed to generate lots of new knowledge in the 20th century, Mr Jones says, they are themselves subject to diminishing returns. (The share of a population working in R&D can only rise so high, for example, and as it does the productivity of each additional researcher is likely to drop.) A decline in the absolute number of brains might thus place a serious dampener on innovation, he writes, and thus on prospects for continued growth in incomes. Using a simple model, Mr Jones suggests that the world may face two potential outcomes in future. If fertility stabilises at a high enough level, an “expanding cosmos” scenario awaits, in which the stock of knowledge, population and incomes all rise ever upward. Alternatively, a cycle of falling population and reduced idea creation could lead to an “empty planet” outcome, in which living standards stagnate while population figures dwindle.

但是新想法本身需要被生成。一个经济体可以通过调整人力资源部署来产生更多想法：比如在教育上增加投资，鼓励更多人从事研究而非生产。但是，琼斯指出，尽管这些解决方案在20世纪带来了许多新知识，它们本身仍要服从收益递减的规律。(比如研究人员占人口比例只能增长到某个水平，而这时每个新增研究人员的生产率很可能下降。)因此，他写道，大脑绝对数量的减少可能会严重抑制创新，从而影响收入持续增长的前景。琼斯用一个简单的模型展示了未来世界可能面对两种结果。如果生育率稳定在一个足够高的水平、等待我们的情境是“膨胀的宇宙”一一知识储备、人口和收入都不断上升。另一种结果是，人口减少，产生的想法减少，这样的循环可能导致一个“空荡荡的地球”，生活水平随人口减少而停滞不前。

Models like Mr Jones’s are less interesting as literal descriptions of how economies work than as illustrations of how different factors might affect future economic developments. It is possible, for instance, that computing advances might increase the productivity of research, or even enable the automation of some forms of idea generation, reducing the constraint he identifies.

相比于准确描述经济的运行方式，像琼斯提出的这类模型更有趣的地方是展示不同因素可能如何影响未来的经济发展。比如，计算的进步可能会提升研究领域的生产率，甚至让想法的生成实现某种形式的自动化，减少他指出的制约因素。

At the same time, his work gestures at underappreciated sources of complacency. Rich economies may have worried too little about the growing numbers of researchers needed to generate steady improvement in computing power, for instance, out of a misguided assumption that there will always be more people available to don a lab coat. They may also have undervalued human potential more generally: by failing to prioritise education, or welfare programmes which might allow households that would like to have children to do so comfortably, with the same urgency as they have looked after other critical resources. Strangest of all, in the eyes of future inhabitants of an emptying planet, may be rich governments’ present disquiet at fast-growing populations in the developing world. That advanced economies did not invest lavishly in the talents of the world’s poorer billions may come to look existentially foolhardy.

同时，他的研究指出了一些被低估的自满情绪。比如要让计算能力稳步提升，研究人员的数量需要不断增加，而富裕经济体对此可能担忧得太少了，它们错误地认为总会有越来越多的人等着穿上实验室白大褂。它们可能也更广泛地低估了人力潜能：相比对其他关键资源的关切，像教育或福利这些能为想要生儿育女的家庭提供便利的项目没有得到同等重视。在未来空荡荡的地球上的居民看来，最奇怪的可能是富裕国家的政府在今天对发展中国家人口的迅猛增长深感忧虑。发达经济体没有慷慨投资于世界上数十亿较贫穷人口中的人才，在一个关乎人类生存的问题上它们可能显得太过草率了。