宮川 努

コロナ禍を経た日本で、デジタル化の遅れを取り戻す動きが盛んになっている。しかし、統計データの制約から IT 投資とそれに伴う人材育成や組織改革を組み合わせた包括的なデジタル化に関する定量的な分析は少ない。一方で従来型の投資ではないクラウド・サービスや生成AIなどの新たな情報サービスの利用形態も現れている。そこで本稿では、統計データの制約の下で、生産に寄与する IT 資産及び IT サービスの計測に関する新たなアプローチを試みる。またデジタル化を政府が推進する背景には、スピルオーヴァー効果の存在があるが、本稿では公的部門と情報サービス産業からのスピルオーヴァー効果に焦点をあてた推計を行う。推計の結果、これらの産業からのスピルオーヴァー効果が確認されたことから、もしスピルオーヴァー効果を重視するのであれば、政府の支援は情報サービス産業を中心にした方が望ましいと考えられる。

The economic impact of information and communications technology (ICT) investment is visible only with a long time-lag, particularly in the case of employment. There are two contrasting effects of ICT investment on employment: the complementarity relationships between capital and higher skills and the substitutability relationships between capital and lower skills and between the ICT capital intensity and wage rate of unskilled workers. The purpose of this paper is to provide empirical evidence on the impact of the skill-biased technical change associated with ICT investment on labor demand in Japan and Korea. Our estimates of the effect of ICT intensity on the wage share based on Japanese and Korean data are generally consistent with the estimates obtained by O'Mahony et al. (2008) in the sense that we find capital-skill complementarity and technology-skill substitutability during the period 1995-2015.

Following Corrado et al. (Review of Income and Wealth 55:658–660, 2009), we measure intangible assets at the listed firm level in Japan. Compared to the conventional Tobin’s Q, the revised Q including intangibles is almost 1 on average, as suggested by Hall (Brookings Papers on Economic Activity 1:73–118, 2000 and American Economic Review 91:1185–1202, 2001). The standard deviation of the revised Q is smaller than that of the conventional Q. Estimation results based on Bond and Cummins (Brookings Papers on Economic Activity 1:61–124, 2000) show that greater intangible assets increase firm value. In particular, in the IT industries, on average Tobin’s Q is higher than that in the non-IT industries, and the stock market reflects the value of intangibles in the IT industries. These results suggest that the government should adopt policies that promote investment, including intangibles in the IT industries, and change in industry structure in Japan.

新たに作成された地域別・産業別生産性データベースと社会資本のデータを組み合わせて，社会資本の生産力効果を再検証した．我々の推計では，バブル崩壊後に全産業にわたって生産力効果が見られる．これはバブル崩壊後財政が悪化し，社会資本投資が抑制的に運営される中で，効率的な投資配分が行われてきたことを示唆している．推計結果から計測される社会資本の収益率は，総じて民間資本より高いが，これは非製造業において顕著である．また民間資本の収益率は地域差がほとんどないが，社会資本の収益率やトービンのＱは地域差が大きく，都市部以外の地域に社会資本が重点的に配分されたことを示している．This paper reexamines the effects of public capital on productivity growth at the regional level by using the Regional Japan Industrial Productivity Database. When we estimate a production function including public capital in TFP, we find positive and significant effects of public capital on productivity growth after the collapse of the bubble economy. Our results imply that public investment after 1991 was allocated more efficiently than before 1990, because total public expenditures have decreased since the mid 1990s. However, the dispersion of the estimated rate of return on public capital and its Tobin's Q has expanded since 1991. This implies that the government has allocated public capital to rural areas more heavily than to urban areas.

In this paper we examine empirically the effect of market competition on firm productivity improvements using data drawn from the Japanese manufacturing sector. We find that a non-linear relationship between competition and productivity growth induced by R&D activity as suggested by Aghion et al. (2005) holds for Japanese manufacturing firms. We also SLOW that greater market competition widens technology differences across firms, and firms facing more intense competition are more productive than other firms. Our empirical results imply that productivity improvement through R&D activity depends on not only a competitive environment but also technological differences between firms. (C) 2012 Elsevier B.V. All rights reserved.