Sorry Janet, market already did your work for you

Janet Yellen
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Goldman Sachs economists say the volatile markets may have done some of the Fed's tightening for it, and that fits well with their call of no rate hike until December.

In a note, the economists point out their Goldman Sachs financial conditions index has tightened by about 50 basis points since early August. The index incorporates such things as stock prices, exchange rates, interest rates and credit spreads.

Financial conditions are a metric the Fed will most certainly consider when it meets next week to discuss the first rate increase in nine years. The Street is very divided on whether the central bank will take action or not this month, and the recent market maelstrom is seen as a key reason why it may hold off.