Needless to say, households and private firms are the main players in a market economy, but a market economy sometimes may not function well. Therefore, the government and public institutions would need to complement it properly.
Price stability is one of the areas in which public institutions should be involved.6  The principle of the Bank's monetary policy is stipulated by the Bank of Japan Act. Article 2 prescribes that "[c]urrency and monetary control by the Bank of Japan shall be aimed at achieving price stability, thereby contributing to the sound development of the national economy."