The magnitude of the Liberal Democratic Party's win in Sunday's general election smooths the path for fiscal stimulus in early 2013 as incoming Prime Minister Shinzo Abe seeks to end the economy's contraction.
The two-thirds majority won by the LDP-New Komeito coalition in the Lower House enables it to override most decisions by the opposition-controlled Upper House. The upper chamber will still have a say on Abe's picks for leaders of the Bank of Japan, as votes on nominations can't be overridden.
The scale of the victory may accelerate a recovery from recession next year, even amid Japan's status as the nation with the world's biggest public debt. The yen fell to a 20-month low against the dollar Monday as markets assess the chance of further pressure on the BOJ to expand asset purchases this week for the fourth time in three months.