And there are long, variable lags before policy changes have any effect on the economy.

政策的变化在对经济产生影响前会有一段比较长且变化莫测的后滞期。

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The link between interest rates and inflation is uncertain. And there are long, variable lags before policy changes have any effect on the economy.

利率和通货膨胀之间的联系无法确定，政策调整对经济的影响既滞后又难以确定。

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Central banks may enjoy their new powers, yet it could be argued that monetary policy is not well suited to this role, as its effects on the economy are felt only after long and variable lags.

ECONOMIST: Fiscal flexibility

The time lag averages roughly four quarters, 12 months, but Friedman said not only that the time lags are long, but also that they are variable.

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