CEP Discussion Paper No 1496 September 2017 Are Ideas Getting Harder to Find ?

In many growth models, economic growth arises from people creating ideas, and the long-run growth rate is the product of two terms: the effective number of researchers and their research productivity. We present a wide range of evidence from various industries, products, and firms showing that research effort is rising substantially while research productivity is declining sharply. A good example is Moore’s Law. The number of researchers required today to achieve the famous doubling every two years of the density of computer chips is more than 18 times larger than the number required in the early 1970s. Across a broad range of case studies at various levels of (dis)aggregation, we find that ideas—and in particular the exponential growth they imply — are getting harder and harder to find. Exponential growth results from the large increases in research effort that offset its declining productivity.

在许多增长模型中，经济增长源于人们创造的想法，而长期增长率是两个因素的乘积：研究人员的有效数量及其研究生产率。我们从各个行业、产品和企业中提供了大量证据，表明研究投入大幅增加，而研究生产率却急剧下降。摩尔定律就是一个很好的例子。如今，要实现计算机芯片密度每两年著名的翻倍，所需的研究人员数量是20世纪70年代初所需数量的18倍多。在不同（分解）层次的大量案例研究中，我们发现想法——尤其是它们所暗示的指数增长——越来越难以寻觅。指数增长是研究投入的大幅增加抵消了其生产率下降的结果。