Former Bank of Japan Policy Board member Sayuri Shirai says the central bank has done about all it can do to end the nation's deflationary mindset.

More than four years ago it unleashed massive monetary easing, but taxpayers still doggedly save, fearing that public pensions won't provide enough for their retirement. The government must build public trust in its ability to safeguard public pensions, Shirai says.

Now a professor at Keio University, Shirai was one of nine board members who helped decide monetary policy between 2011 and 2016, a time when the BOJ engaged in the greatest monetary experiment in central banking history. She served Govs. Masaaki Shirakawa and Haruhiko Kuroda as the only female board member at the time and was the third to have ever held the role.