Negative information or adverse effects (option A) leads to a leftward shift. Decrease in the price of substitutes (option B), positive information about health benefits (option C), and a new diet recommendation (option D) lead to rightward shifts in the demand curve.
Let's match the non-price determinants of demand with the type of shift in the demand curve they are likely to cause:
1. Research shows that olive oil consumption leads to hair loss (A):
Type of shift: Leftward shift
Negative information about the product (hair loss in this case) is likely to decrease the demand for olive oil, causing a leftward shift in the demand curve.
2. A decrease in the price of other vegetable oil (B):
Type of shift: Rightward shift
A decrease in the price of a substitute (other vegetable oil) would make olive oil relatively more attractive, increasing the demand for olive oil and causing a rightward shift in the demand curve.
3. A report in the news stating that consumption of olive oil improves health (C):
Type of shift: Rightward shift
Positive information about the health benefits of olive oil is likely to increase the demand for it, causing a rightward shift in the demand curve.
4. A popular new diet prescribes only olive oil for weight loss (D):
Type of shift: Rightward shift
A new diet that prescribes only olive oil for weight loss is likely to increase the demand for olive oil, causing a rightward shift in the demand curve.