Food, Income, And The Desire For Variety
Recent research on the relationship between food choices and income has shown that consumers often demand a greater variety of food and diversify their diets as incomes rise. This is frequently understood as reflecting the increased ability of more affluent consumers to satisfy their unique tastes and preferences. However, other reasons for the link between higher income and increased diversity of consumers’ diets remain underexplored.
Explaining Food Preference Reversals
Researchers wanted to examine the relationship between a consumer’s preference stability — the consistency of their food choices — and income/weekly spending on food.
Data for this study came from a choice experiment featured in the monthly online Food Demand Survey, which draws at least 1,000 new respondents each month. Researchers used surveys collected over a 59-month period, from June 2013 to April 2018. Respondents answered nine different simulated shopping scenarios or multiple choice questions. For each multiple choice question, respondents were presented with the same eight food items (plus a “none” option). Prices assigned to the products varied across the nine questions, with each item having a low, medium or high price in different scenarios or questions.
Researchers checked each of the respondent’s nine choices for preference reversals. A preference reversal was identified when a respondent chose item A over item B, when A was more expensive than B (indicating that they preferred item A), but then in a later choice the same respondent chose item B over item A when B was more expensive than A (indicating that they preferred item B). In other words, preference reversal shows a lack of consistency or rationality on the part of the consumer. Researchers noted the number of preference reversals committed by each respondent, and compared this to their household expenditure on both food for the home and food to consume away from home.
Of the 59,979 respondents, 47% showed at least one preference reversal. The average number of preference reversals across the entire sample was 1.33, and of the 47% who had at least one reversal, the mean number of reversals was 2.84.
The researchers found that the prevalence of preference reversals increases with higher at-home food expenditure. Of the households who spent less than $20 per week on food at home, 37% committed a preference reversal. By contrast, 53% of households who spent $160 per week or more on food committed at least one preference reversal. An even stronger positive correlation between expenditure and reversals was found, and it was related to spending on food to consume away from home.
Age, family status, gender, and race also impacted on the odds of preference reversal. Consumers aged 45 to 64 were the least likely to reverse their food preferences compared with those under the age of 25. Households with younger children were around 1.6 times more likely to have a reversal than those without children. Women were 0.76 times less likely to have a reversal than men, and black and African American respondents had higher odds of reversals compared with respondents of other races.
When controlling for demographics, it was found that the likelihood of preference reversal remained significantly higher for households with an annual income of between $60,000 and $159,999, compared to households earning less than $40,000.
Variety and Novelty
Although these kinds of inconsistencies have traditionally been linked to “irrationality” (economically speaking), they might also be a result of greater demand for variety or a preference for new foods. The researchers compared the number of preference reversals to 12 consumer food values, including price, convenience, novelty, and animal welfare.
People with zero preference reversals — those whose choices were most consistent — ranked taste, safety, price, and nutrition as their most important food values. As the number of reversals increased, the relative importance of price fell dramatically, while the relative importance of novelty rose.
The importance of animal welfare — ranked 6th out of 12 for those with zero preference reversals — slightly increased for consumers with more than one reversal, but this was mostly insignificant compared to increases in the importance of novelty, origin, naturalness, and fairness.
A strong desire for variety can help explain reversals, but it doesn’t paint the full picture. After controlling for the desire for novelty, researchers still observed a positive relationship between income/spending and preference reversals, suggesting that factors other than variety or novelty motivate reversal in higher income households.
The study has implications for how researchers have traditionally thought about the relationship between income and healthy food choices; irrationality in one domain (the economics of food choices) might spill over into another (making unhealthy or unethical food choices). On a related note, short-term health-motivated diets and inconsistent but sincere attempts at vegetarian or vegan diets could arguably be considered a form of preference reversal.
The findings of this study may also be relevant to the food marketing industry. Food and agricultural scientists have long held the view that food marketing targeted at more wealthy consumers is “unscientific” in nature. There is not necessarily a relationship between the preference instability observed in more wealthy consumers and “unscientific” beliefs about safe ingredients and food processing. Still, it could be argued that more affluent consumers are more able to seek out sources of information that affirm their beliefs and cultural identities.