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- The Fed will spark a disaster if it delivers a bigger rate hike than expected this week, Jeremy Siegel said.
- The top economist said inflation was falling rapidly, and officials needed to soften policy to avoid a recession.
- "We have to get no more than 25 basis-points. 50 would be I think a disaster," Siegel told CNBC.
The Federal Reserve risks sparking an economic disaster if it hikes rates higher than markets are expecting at its upcoming meeting this week, according to Wharton Professor Jeremy Siegel.