English: Anything that affects the buying decision other than the product price will shift the demand curve.The curve shifts to the left if the determinant causes demand to drop. That means less of the good or service is demanded at every price. Consumers will buy less, even though the price is the same. The curve shifts to the right if the determinant causes demand to rise. That means more of the good or service is demanded at every price. Consumers will now buy more, even though the price has not changed at all.