Complementary goods {Ans: flashlights and batteries, writing pads and pens (an increase in the price of flashlights will result in a decrease on the demand for batteries)}Caused by Non-Price Factors {Ans: Any other changes, other than the price of the product, will result to a SHIFT to the DEMAND CURVE (a NEW demand curve will be formed)}Income {Ans: A buyer's income has a positive effect on demand.}Price of Related Goods or Commodities {Ans: The demand for a good can also be influenced by the prices of related goods}Substitute goods {Ans: beef and pork, rice and bread (an increase in the price for beef will result in an increase in the demand for pork)}Two types of movement of the demand curve {Ans: A. Caused by a change in price B. Caused by non-price factors}