→Causation versus correlation: superfical counterexamples
===Independent shifts of the demand curve===
To understand how the causation and correlation issue can be confused, consider a shift in the demand curve due to a change in one of the other [[determinants of demand]] (i.e., an [[exogenous parameter]] in the interaction between demand and price). If the shift is outward, i.e., if demand increases for every given price, this causes a tendency for the [[market price]] (the price at which the market clears) to rise. This does ''not'' contradict the law of demand, because the change in demand was due to exogenous factors.
===What matters are relative prices -- effects of inflation and simultaneous changes in prices of substitutes===