Interpreting movements along the yield curve

解释收益率曲线的变动

Observers in the financial press often interpret changes to the yield curve as a signal about the current state of the economy and a prediction or warning about the future. A downward sloping yield curve is usually interpreted as a warning of an economic downturn; bond traders anticipate that future central bank policy rates will be low to stimulate the economy.

While a rising yield curve could be a sign of future GDP growth (with the central bank raising its policy rate in response), a sudden rise in long-yields could also indicate financial stress. [Note 1] Whereas a fall in long-yields is a sign that financial stress and deflationary expectations is dissipating, not necessarily that the economy will fall into recession in the near future.

Interpreting movements along the yield curve requires judgement, and depends on our expectations about the future state of the economy. There is a degree of circularity. Fears of a downturn could lead to long-yields falling, and this reinforces the narrative of a weak economy. Whereas fear of financial stress could prompt long-yields to rise suddenly, reinforcing the financial stress narrative.

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Note 1: If the government bonds are held by foreign investors, a sudden rise in long-yields could also indicate concerns over an impending currency depreciation (due to rising trade deficit and fast depleting foreign reserves).

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金融媒体的评论员经常将收益率曲线的变化解释为经济现状的信号以及对未来的预测或警告。向下倾斜的收益率曲线通常被解释为经济衰退的警告；债券交易者预计未来央行的政策利率将较低以刺激经济。

虽然收益率曲线上升可能是未来GDP增长的迹象（央行将提高政策利率以应对），但长期收益率的突然上升也可能表明金融压力担忧。[注1] 而长期收益率下降则表明金融压力和通货紧缩预期正在消退，并不一定意味着经济将在不久的将来陷入衰退。

解释收益率曲线的变动需要判断，并取决于我们对未来经济状况的预期。存在一定程度的循环性。对经济衰退的担忧可能导致长期收益率下降，这强化了经济疲软的叙述。而对金融压力的担忧可能导致长期收益率突然上升，从而强化金融压力的讲述。

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注1: 如果政府债券由外国投资者持有，长期收益率的突然上升可能表明对即将货币贬值的担忧（由于贸易逆差增加和外汇储备快速减少）。