• Professional Career

2007-2008: Researcher, Institute of Intellectual Property.
2008-2011: Research associate, Institute of Innovation Research, Hitotsubashi University.
2011: Ph.D.(Economics), Hitotsubashi University.
2011-2013: Research fellow, Research Institute of Economy, Trade and Industry
2013-present: Associate Professor, National Graduate Institute for Policy Studies

2011-2013: Adjunct Researcher, Institute of Innovation Research, Hitotsubashi University.
2012-2013: Visiting Researcher, National Institute of Science and Technology Policy.
2013-present, Research Associate, Research Institute of Economy, Trade and Industry.

• Selected papers

Nagaoka, Sadao, Naotoshi Tsukada, Koichiro Onishi, and Yoichiro Nishimura (2012) "Innovation Process in Japan in the Early 2000s as Seen from Inventors: Agenda for strengthening innovative capability," RIETI Discussion Paper Series, 12-J-033, (in Japanese).

Tsukada, Naotoshi and Sadao Nagaoka (2011) "Standards as a knowledge source for R&D: A first look at their incidence and impacts based on the inventor survey and patent bibliographic data," RIETI Discussion Paper Series 11-E-018.

Nagaoka, Sadao and Naotoshi Tsukada (2011) "Spillovers and Risk of R&D Projects, and Targeting of Public R&D Support," RIETI Discussion Paper Series 11-J-044, (in Japanese).

Tsukada, Naotoshi, “Essays on Innovations, collaborations and patenting,” Ph.D Thesis, Hitotsubashi University, 2011.

Tsukada, Naotoshi and Sadao Nagaoka, "International R&D Collaborations in Asia: A first look at their characteristics based on patent bibliographic data," in Globlization and Innovation in East Asia (ERIA Research Project Report FY2010), eds. by Chin Hee Hahn and Dionisius Narjoko, Chapter 12, pp.410-451, March 2011.

Nagaoka, Sadao, Naotoshi Tsukada and Tomoyuki Shimbo, "The structure and the emergence of essential patents for standards: Lessons from three IT standards," in Uwe Canter, Jean-Luc Gaffard, Lionel Nesta eds. Schumpeterian Perspectives on Innovation, Competition and Growth, Splinger, August 2009, pp.433-447.

Nagaoka, Sadao, and Naotoshi Tsukada (2009) "R&D generating standards and R&D depending on standards," Hitotsubashi Business Review 57(3), 50-65, (in Japanese).

Nagaoka, Sadao, and Naotoshi Tsukada (2007) "Innovation Process in Japan: Findings from the RIETI Inventors Survey," RIETI Discussion Paper Series 07-J-046, (in Japanese).