The Bank of Japan has failed to adequately analyze the side effects of its massive easing campaign in its comprehensive review of monetary policy over the past 25 years that was published Thursday, economists said.

"The overall effect on the Japanese economy so far appears to have been positive," the central bank said in its report on the review.

But the massive easing policy, introduced in April 2013, has caused adverse effects, such as a loosening of fiscal discipline and a delay in restructuring industries that slowed economic growth, economists said.