The Impact of Military Technology Development on Innovation: Evidence from Prewar and Wartime Japanese Secret Patents

Kotani, Atsuki：Kentaro Nakajima：Tetsuji Okazaki：Yukiko U. Saito
25-E-093 RIETI Discussion Paper Series （2025/09/01）

Innovations in military technology potentially drive significant societal transformations through applications to civilian use. This study aims to quantitatively measure the impact of military technology development on civilian innovation activities using prewar and wartime Japanese patent data from 1916 to 1945. By exploiting Japan's …

The role of human interaction in innovation: evidence from the 1918 influenza pandemic in Japan

Inoue, Hiroyasu：Kentaro Nakajima：Tetsuji Okazaki：Yukiko U. Saito
『The Japanese Economic Review』 Vol.76 No.3 pp.795-820 （2025/06/19）

This study empirically investigates human interaction’s role in innovation by exploiting the 1918 influenza pandemic in Japan from 1918 to 1921, which prohibitively incr…

Invention by Collage Graduates in Science and Engineering during Japan's Industrialization

Yamaguchi, Shotaro：Hiroyasu Inoue：Kentaro Nakajima：Tetsuji Okazaki：Yukiko Umeno Saito：Serguey Braguinsky
22-E-104 RIETI Discussion Paper Series （2022/11/01）

During Japan's industrialization from the late 19th to the first half of the 20th century, the adoption of foreign technologies was　increasingly complemented by domestic…

Language Barriers and the Speed of Knowledge Diffusion

Higham, Kyle: Sadao Nagaoka
22-E-074 RIETI Discussion Paper Series （2022/08/18）

The Role of Face-to-face Contact in Innovation: The Evidence from the Spanish Flu Pandemic in Japan

Inoue, Hiroyasu： Kentaro Nakajima： Tetsuji Okazaki： Yukiko Umeno Saito
22-E-026 RIETI Discussion Paper Series （2022/03/01）

Local Industry Influence on Commercialization of University Research by University Startups

Kang, Byeongwoo : Kazuyuki Motohashi
20-E-086 RIETI Discussion Paper Series （2020/11/01）

Book Review: Jinzai no kokusai ido to inobeshon (International Migration of Highly Skilled Workers and Innovation, by Yukiko Murakami, Tokyo: NTT Publishing, 2015)

Nakajima, Kentaro
『Social Science Japan Journal』 Vol. 20 No. 2 pp.323-325 （2017/08/01）

Descriptive analysis of the knowledge network formation in East Asia

Nabeshima, Kaoru : Byeongwoo Kang : Mila Kashcheeva
『Technology in Society』 Vol.47 pp. 66-100 （2016/11/01）

This paper shows descriptively how the knowledge network in East Asia has been formed. In addition, the correlation between the knowledge network and economic growth is also examined. Evidence is provided to show that plugging into the knowledge network of developed economies could be a key for increasing innovativeness in an economy.

Testing for localization: A new approach

Murata, Yasusada : Ryo Nakajima : Ryuichi Tamura
WP#16-11 Hitotsubashi University IIR （2016/08/19）

Recent empirical studies document that knowledge spillovers attenuate and industry localization decays with distance. It is thus imperative to detect localization accurately especially at short distances. We propose a new approach to testing for localization that corrects the first-order bias at and near the boundary in existing method…