The Economics of Spatial Mobility: Theory and Evidence Using Smartphone Data

Miyauchi, Yuhei：Kentaro Nakajima：Stephen J Redding
『Quarterly Journal of Economics』 Vol.140 Issue 4 pp.2507-2570 （2025/11/01）

We develop a tractable quantitative framework for modeling the rich patterns of spatial mobility observed in smartphone data. We show that travel is frequently undertaken as part of a travel itinerary, defined as a journey starting and ending at home that can include more than one intermediate stop on a given day. We show that these tr…

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…

Correlation aversion in foreign direct investment

Khotamov, Navruz：Naoto Jinj
『Finance Research Letters』 Vol.74 pp.1-5 （2025/03/01）

Decisions under risk are often multidimensional, where the preferences of the investor depend on several factors. Investment theory implies that in the presence of different shocks, the correlation between these shocks is important. This study analyzes the relationship between the correlation of two shocks and foreign direct investment…

血肉化するイノベーション：革新を実現する組織を創る

軽部大： 山田仁一郎 （訳）, ベン・Ｍ・ベンサウ （原）Built to Innovate：Essential Practices to Wire Innovation into Your Company's DNA
中央経済社（2025/02/26）

イノベーションは身近なものである。イノベーションの実現に必要な活動が日々の活動として習慣化するためには何をすべきか。企業の事例を交えながら具体的な方法を提示する。

Exports and foreign direct investment in the presence of downside risk

Khotamov, Navruz
『The World Economy』 （2024/11/25）

This study analyses the impact of downside risk on the flow of exports, foreign direct investment (FDI), and their joint pattern. Existing studies in this field have not considered the effects of risk asymmetry or downside risk because they describe risk only by variance; therefore, this study attempts to fill this gap. Downside risk i…

The Impact of Brokerage in a Communication Network on Productivity: Evidence from Sensor Data

Nakajima, Kentaro：Tsuyoshi Tsuru：Katsuhito Uehara
『Connections』 Vol.44 Issue1 1-20頁 （2024/05/29）

Problem-solving effectiveness is key to organizational performance. To solve problems, gathering information from colleagues is critical, and positioning brokerage in communication networks is beneficial. The communication network for problem-solving is formed depending on the nature of the problem. Thus, the problem-solving network i…

From Samurai to Skyscrapers: How Transaction Costs Shape Tokyo

Yamasaki, Junichi：Kentaro Nakajima：Kensuke Teshima
E-2020-02 TDB-CAREE Discussion Paper Series （2023/02/01）

Whether transaction costs to assemble or split land can persistently hinder urban land use remains unknown. Constructing a 100 m*100 m-cell-level dataset of central Tok…

Satellite-Based Vehicle Flow Data to Assess Local Economic Activities

Go, Eugenia：Kentaro Nakajima：Yasuyuki Sawada：Kiyoshi Taniguchi
F-1209 CIRJE Discussion Paper Series （2023/01/01）

Spatially and seasonally granular measures of local economic activities are increasingly required in a variety of economic analyses. We propose using novel vehicle density data obtained from daytime satellite images to quantify the local economic activity involving human and goods traffic flows. Validation exercises show that vehicle …

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 Economics of Spatial Mobility: Theory and Evidence Using Smartphone Data

Miyauchi, Yuhei： Kentaro Nakajima： Stephen J. Redding
No. 28497 NBER Working Paper （2022/04/01）

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）

On the Use of Satellite-Based Vehicle Flows Data to Assess Local Economic Activity: The Case of Philippine Cities

Go, Eugenia： Kentaro Nakajima： Yasuyuki Sawada： Kiyoshi Taniguchi
No. 652 ADB Economics Working Paper Series （2022/03/01）

Local Labor Market Effects of Chinese Imports and Offshoring: Evidence from Matched-Foreign Affiliate-Domestic Parent-Domestic Plant Data in Japan

Kiyota, Kozo： Kentaro Nakajima： Miho Takizawa
22-E-13 RIETI Discussion Paper Series （2022/03/01）

The Roles of Structured Management in the Formation of Transactional Relationship

Imani, Yusuke: Atsushi Ohyama
E-2021-07 TDB-CAREE Discussion Paper Series （2022/02/01）

Product Innovation, Product Diversification and Firm Growth: Evidence from Japan's Early Industrialization

Braginsky, Serguey: Atsushi Ohyama: Tetsuji Okazakii: Chad Syverson
『American Economic Review』 Vol. 111 No. 12 pp. 3795-3826 （2021/12/01）

Economic sociology in Japan

Nakano Tsutomu: Masaru Karube: Yoshimichi Sato: Naoki Wakabayashi
『economic sociology. perspectives and conversations』 23 1 11-18 （2021/11/30）

Economic sociology is an established field in the Western tradition of sociology. Departing from the instrumental rationality of neoclassical economics (Weber 1968), it has made a breakthrough with its foundational conception that economic action of individuals constructs social structures and these social structures heavily influence …

Estimating the Impact of Land Use Regulation on Land Price: At the Kink Point of Building Height Limits in Fukuoka

Nakajima, Kentaro： Keisuke Takano
21-E-88 RIETI Discussion Paper Series　21-E-88 （2021/10/01）

Management practices and productivity in Japan: Evidence from six industries in JP MOPS

Kambayashi, Ryo: Atsushi Ohyama: Nobuko Hori
『Journal of the Japanese and International Economies』 Volume 61 （2021/09/01）