The cross-price elasticity between two products is found to be half. From this, we know that the two product are

Normal
Inferior
Necessities
Complements

The correct answer is: Complements.

The cross-price elasticity of demand measures how the demand for one good changes in response to a change in the price of another good. If the cross-price elasticity is positive, then the two goods are substitutes. If the cross-price elasticity is negative, then the two goods are complements.

A value of 0.5 for the cross-price elasticity indicates that a 1% increase in the price of one good will lead to a 0.5% decrease in the demand for the other good. This suggests that the two goods are complements, as a decrease in the price of one good will lead to an increase in the demand for the other good.

Here is a brief explanation of each option:

  • Normal goods are goods whose demand increases when income increases. For example, if your income increases, you may decide to buy a new car.
  • Inferior goods are goods whose demand decreases when income increases. For example, if your income increases, you may decide to eat out less often.
  • Necessities are goods that are essential for survival. For example, food and water are necessities.
  • Complements are goods that are used together. For example, cars and gasoline are complements.