【2015年，中国决策者将制定“十三五”规划。他们面临一个基本问题：增长目标定在多少？

有人抛出“十三五经济增长6.5%即可”论，认为“‘十三五’期间只需保持6.5%的年均增长速度，即可实现党的十八大报告提出的到2020年GDP比2010年翻一番的目标。但经济学家林毅夫赐稿观察者网，他在文中认为，在为下一个五年制定计划时，决策者应该将增长目标定在7%~7.5%，这一增长目标，将有助于稳定就业、降低金融风险、实现2020年收入翻番的目标。 】

在市场经济改革以来的35年中，中国的平均增长率高达9.8%——这是前所未有的爆炸式增长。但有迹象表明，中国奇迹正在走向终点——或者至少经济增长正在放缓。

自2010年第一季度以来，中国的增长率一直在下降。2014年第三季度，经济增长率降到了相对较低的7.3%。

随着2014年临近尾声，中国的经济增长可能将继续面临强劲的逆风，至少与前几十年相比是如此。2015年，决策者将制定中国的“十三五”规划。他们将面临一个基本问题：增长目标定在多少？

在制定一国GDP目标时，首先要明白经济的潜在增长率，即假设内部和外部条件有利、未来增长稳定性与可持续性不会受到威胁的情况下的最快扩张速度。亚当·斯密在《国富论》中论证了经济增长取决于劳动生产率的改善。而今天，劳动生产率的改善要么来自技术创新，要么来自产业升级（将产能重新配置给更高附加值的新部门）。

但位于创新前沿的发达国家处于劣势。要想从新技术中获益，它们就必须创造新技术。相反，发展中国家拥有“后发优势”，因为它们可以通过模仿、进口、综合和许可实现技术进步。结果，它们的成本和风险更低。过去150年中，发达经济体平均每年增长3%，而一些发展中国家在20年甚至更长的时间里保持着7%甚至更高的年增长率。

中国在经历了35年前所未有的经济增长之后，还剩下多少后发优势？我们需要考察其技术和产业发展水平与高收入国家的差距。考察这一差距的最佳办法是比较经购买力平价(PPP)调整的人均收入。人均收入差距越大，后发优势和增长潜力也就越大。

2008年，中国人均收入只有美国的五分之一略多。这一差距大致相当于1951年美国和日本之间的差距，在此之后的20年里，日本平均年增长率为9.2%；这一差距也大致等于1977年美国和韩国之间的差距，在此之后的20年里，韩国年增长率为7.6%。1967年的新加坡和1975年的中国台湾地区也有类似差距——此后也出现了类似的增长率。由此类推，在2008年后的20年里，中国的潜在增长率应在8%左右。 

但潜在增长率只是故事的一部分。它是否可以实现，取决于国内条件和国际环境。为了利用后发优势，中国必须深化改革，消除经济中残留的扭曲因素。与此同时，政府应该更主动地克服市场失灵——如外部性和协调问题——这些失灵是伴随技术创新和产业升级而来的不可避免的现象。

中国有潜力通过内需——不仅是家庭消费——保持“鲁棒”(Robust，健壮和强壮)增长。中国不缺少投资机会，有充分的产业升级空间和足够的潜力改善城市基础设施、公共住房和环境管理。

此外，中国的投资资源十分丰富。中央和地方政府债务总和还不到GDP的50%——以国际标准衡量属于低水平。与此同时，中国的私人储蓄相当于GDP的近50%，外汇储备高达4万亿美元。即使面临相对不利的外部条件，中国也可以在短期内依靠投资创造就业；而随着就业岗位数量的增加，消费也会水涨船高。

但是，外部环境会更加令人沮丧。尽管发达国家在2008年全球金融危机后进行了强力干预，启动了大规模财政和货币刺激手段，但很多发达国家的结构缺陷仍没有解决。日本的“安倍经济学”收效甚微，欧洲央行正在步美国和日本的后尘，试图用量化宽松提振需求。

美国的就业正在增加，但劳动力参与率仍然不高，经济也没有达到衰退后反弹通常可以达到的6%~7%。美国、欧洲和日本可能将经历持续低迷，抑制中国的出口增长。

因此，中国的增长可能会低于每年8%的潜在增长率。在为下一个五年制定计划时，决策者应该将增长目标定在7%~7.5%，并在此范围内根据国际气候变化调整。这一增长目标有助于稳定就业、降低金融风险、实现2020年收入翻番的目标。

（翻页查看英文版，英文版首发于Project-Syndicate）

By Justin Yifu Lin

In the 35 years since China's transition to a market economy began, the country has grown at an average rate of 9.8 percent - an explosive and unprecedented rise. But there are signs that the Chinese miracle is coming to an end - or at least that the country's economic growth is slowing. China's growth rate has been falling since the first quarter of 2010. In the third quarter of 2014, it was a relatively anemic 7.3 percent.

As 2014 winds down, China's economic growth is likely to continue to face stiff headwinds, at least when compared to previous decades. As policymakers in 2015 draw up the country's 13th Five-Year Plan (2016-20), they will grapple with a fundamental question: How fast can China expect to grow?

In setting a country's GDP target, the first thing to understand is the economy's potential growth rate: the maximum pace of expansion that can be attained, assuming favorable conditions, internally and externally, without endangering the stability and sustainability of future growth. As Adam Smith discussed in An Inquiry into the Nature and Causes of the Wealth of Nations, economic growth depends on improvements in labor productivity, which today result from either technological innovation or industrial upgrading.

But developed countries at the innovation frontier are at a disadvantage. To benefit from new technology, they must create it. Developing countries, by contrast, possess a "latecomer advantage", because they can achieve technological advances through imitation, importation, integration, and licensing. As a result, their costs and risks are lower. Over the last 150 years, developed economies have grown at an average rate of 3 percent per year, whereas some developing countries have achieved annual growth rates of 7 percent or higher for periods of 20 years or longer.

To calculate how much of a latecomer advantage China has after 35 years of unprecedented growth, one needs to look at the gap between its levels of technological and industrial development and those of high-income countries. The best way to see this is by comparing its per capita income, adjusted for purchasing power parity with those of developed countries: The larger the gap in per capita income the larger the latecomer advantage and the greater the potential for growth.

In 2008, China's per capita income was just over one-fifth that of the United States. This gap is roughly equal to the gap between the US and Japan in 1951, after which Japan grew at an average annual rate of 9.2 percent for the next 20 years, or between the US and South Korea in 1977, after which South Korea grew at 7.6 percent per year for two decades. Singapore in 1967 had similar gaps - followed by similar growth rates. By extension, in the 20 years after 2008, China should have a potential growth rate of roughly 8 percent.

But potential growth is just one part of the story. Whether it can be achieved depends on domestic conditions and the international environment. In order to exploit its latecomer advantage, China must deepen its reforms and eliminate its economy's residual distortions. Meanwhile, the government should play a proactive role in overcoming the market failures - such as externalities and coordination problems - that are certain to accompany technological innovation and industrial upgrading.

China has the potential to maintain robust growth by relying on domestic demand - and not only household consumption. The country suffers no lack of investment opportunities, with significant scope for industrial upgrading and plenty of potential for improvement in urban infrastructure, public housing and environmental management.

Moreover, China's investment resources are abundant. Combined central and local government debt amounts to less than 50 percent of GDP - low by international standards. Meanwhile, private savings in China amount to nearly 50 percent of GDP, and the country's foreign exchange reserves have reached $4 trillion. Even under comparatively unfavorable external conditions, China can rely on investment to create jobs in the short term; and as the number of jobs grows, so will consumption.

The external scenario, however, is gloomier. Though developed countries' authorities intervened strongly in the aftermath of the global financial crisis in 2008, launching significant fiscal and monetary stimulus measures, many of their structural shortcomings remain unresolved. "Abenomics" in Japan has yet to yield results, and the European Central Bank is following in the footsteps of America and Japan, pursuing quantitative easing in an effort to shore up demand.

Employment in the US is growing, but the rate of workforce participation remains subdued and the economy has yet to attain the 6 to 7 percent growth rates usually recorded in a post-recession rebound. The US, Europe, and Japan are likely to experience continued sluggish performance, inhibiting China's export growth.

As a result, Chinese growth is likely to fall below its potential of 8 percent a year. As policymakers plan for the next five years, they should set China's growth targets at 7 to 7.5 percent, adjusting them within that range as changes in the international climate dictate. Such a growth target can help to stabilize employment, lower financial risks, and achieve the country's goal of doubling incomes by 2020.