Japan’s labor market is showing “significant improvement,” though it still faces challenges including a large share of part-time workers in the service sector, Bank of Japan Governor Haruhiko Kuroda said on Saturday. Wage growth is critical to reverse deflation and for that to happen “it is necessary to have some kind of coordinated mechanism,” Kuroda said at a central banking conference here, adding that the Bank of Japan’s quantitative easing stimulus is helping Japan escape from a deflationary cycle of falling wages and demand.