A study by Duke University researchers shows that consumers tend to avoid the largest and smallest soft drink options regardless of the actual volume of the drink, according to a Journal of Consumer Research report presented in Science Daily.
Duke University researchers Kathryn M. Sharpe, Richard Staelin and Joel Huber said that the basic premise of the research shows “consumer purchases are altered by the portfolio of drink sizes made available.”
In an attempt to boost profit margins, for instance, quick-service restaurants have eliminated smaller drink sizes and added even larger sizes. The authors believe these policies have led to a 15% increase in the consumption of high-calorie soft drinks.
"Consumers who purchased a 16-ounce drink when a 12-ounce drink was available later chose a 21-ounce drink when the 12-ounce drink option was removed, since now the 16-ounce soda is the smallest option," the researchers found. "This effect also occurred at the large end of the spectrum; people who purchased a 21-ounce drink when the 32-ounce drink was the largest size available moved up to the 32-ounce drink when a 44-ounce drink was added to the range of drink sizes available."
By adding the 44-ounce option, the QSRs are able to shift the demand curve upward, even though the authors said they believe customers still want 12-ounce drinks.