The first thing to remember about the law of  demand is “all else constant.” What we are holding constant includes expected future prices.  This from the Financial Times:

Chinese consumers, increasingly alarmed at the rising cost of living, cleared supermarket shelves this week of shampoos, soaps and detergents after state media said four consumer goods companies … would raise prices by between 5 per cent and 15 per cent.

Via Marginal Revolution.