Final answer:
The demand for rice will probably increase if the price of potatoes goes up, as consumers look for cheaper alternatives. Other factors influencing demand include taste preferences, population changes, income levels, the prices of complementary goods, and future price expectations.
Step-by-step explanation:
If the price of potatoes increases greatly, then the demand for rice (a substitute good) will probably increase. This is based on the principle that when the price of a substitute good increases, consumers look for cheaper alternatives. Following the concept that a price increase of a substitute leads to a higher demand for the related good, consumers may turn to rice as it becomes a more cost-effective option.
In addition to price changes, several other factors can affect demand. These include a taste shift to greater popularity, an increase in the population likely to buy, a rise in income (for a normal good), the price of complements falling, and consumer expectations about future prices. If people anticipate a price rise in potatoes, they might increase their demand for rice now.