The economy took a bigger hit from last month's disaster than anticipated, with factory output falling the most since at least the end of Allied Occupation, underscoring calls for the Bank of Japan to add stimulus.

Factory output dropped a record 15.3 percent from February and household spending plunged 8.5 percent from a year earlier, government reports showed Thursday. Retail sales fell the most in 13 years, according to data released the previous day.

The economy's deterioration makes harder Prime Minister Naoto Kan's task of sustaining confidence in government debt after Standard & Poor's on Wednesday downgraded its outlook for the nation's rating.