By Leika Kihara
TOKYO (Reuters) - The head of the Bank of Japan said on Monday that monetary policy has a substantial impact not only on prices but also on financial system stability by affecting various asset prices.
"Investment in high-risk assets such as high-yield bonds and emerging economies' bonds and stocks has been expanding considerably against a backdrop of declining volatility in interest rates, stock prices, and foreign exchange rates, as well as investors' search for yields," Haruhiko Kuroda said in a speech to the International Bankers Association of Japan.
The burst of Japan's asset bubble in the 1990s is evidence that an economic downturn and banking-sector problems could reinforce each other to create "substantial" imbalances in the economy, he added.
"In any event, central banks cannot be unconcerned about the stability of the financial system," Kuroda said.
There has been considerable debate among central banks of advanced economies on whether their ultra-easy monetary policies are sowing the seeds of a bubble as diminishing returns from low bond yields prompt banks to engage in excessive risk-taking.
Kuroda has rarely spoken in depth on financial stability risks, preferring to emphasise the importance of maintaining the BOJ's massive stimulus to achieve its inflation target.
On Japan's financial system, Kuroda repeated that it has maintained stability with no indication of overheating or excess risk-taking by financial institutions.
The BOJ unleashed an intense burst of monetary stimulus in April 2013, pledging to double base money, to achieve the 2 percent price goal in roughly two years. It has stood pat since then, sounding confident that the economy is on track.
However, private-sector economists see the inflation goal as hard to meet, with some expecting further monetary easing in the coming months after a spate of weak data.
(Reporting by Leika Kihara; Editing by Chris Gallagher)