A former top Japanese financial official said on Wednesday yen weakness might be caused not only by interest rate differentials between Japan and the United States but also by structural factors such as a worsening fiscal position. Under such circumstances, any currency intervention by authorities would not help turn around the market tide to sustain impacts, although smoothing operations may be acceptable, a former vice finance minister for international affairs, Rintaro Tamaki, told Reuters."Confidence in Japan's public finances, falling competitiveness, ageing population and dwindling labour force may be ... (full story)