Citigroup Chief Economist Willem Buiter lashed out against Japanese Prime Minister Abe's fiscal policies on Tuesday, saying the latest package was insufficient.
"Japan has to get serious about sustained, large-scale, continuing stimulus until inflation hits the 2 percent target," Buiter told CNBC's Squawk Box ahead of Abe's announcement of a 13.5 trillion yen ($132.04 billion) package of fiscal stimulus aimed at reviving the flagging Japanese economy.
While the move was welcomed, Buiter warned that a one-time injection wasn't enough to boost an economy mired in deflation. Data for June showed consumer prices dropped for a fourth straight month, while household spending fell in 10 of the past 12 months.
"They have the tools to stimulate demand for goods and services directly in the form of child-care and increased pensions but it has to be on a scale sufficient to do the job ... You have to have continued stimulus until households and corporates are able and willing to keep up spending themselves."