As the price of a commodity rises, overall purchasing power decreases (the income effect) and consumers move toward relatively less expensive goods (the substitution effect).

商品的价格提高，整体的购买力下降(收入效应)，消费者转向购买相对价格低的商品(替代效应)。

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Ad, namely, is to publicize, to make more people know the quality and function of commodity. It is to use real and persuasive propagation to deliver commodity information to create purchasing power.

广告，顾名思义就是广而告之，让人民从广告中了解商品的性能与功用，它通过具有真实性和说服力的宣传来传达商品信息、说服大众、创造购买力。

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In its interim stages, it lifts financial asset prices more than employment, destroys the purchasing power of savings, and may result in much higher commodity prices.

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So, a better way of thinking about the volatility of gold and other commodity prices is to view it as a 40-year period of unprecedented volatility in the price or purchasing power of the dollar.

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During peacetime, commodity standards (silver or gold) worked through market forces to achieve price stability, and thus safeguarded the purchasing power of money.

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