Empirical analysis of the defense interdependence between Japan and the United States

The purpose of this paper is to analyze the defense interdependence between Japan and the United States (US) in the short and long run and to investigate whether Japan is a follower or a free rider of the “US” over the 1975–2009 period. Given that mutual aid between Japan and the US has been maintained, the empirical results suggest that Japanese defense has a stable relationship with US defense. Furthermore, the results reveal that Japan is not a free rider but rather a follower in the period under consideration.