Beyond the sticker price: including and excluding time in comparing food prices.

BACKGROUND
An ongoing debate in the literature is how to measure the price of food. Most analyses have not considered the value of time in measuring the price of food. Whether or not the value of time is included in measuring the price of a food may have important implications for classifying foods based on their relative cost.

OBJECTIVE
The purpose of this article is to compare prices that exclude time (time-exclusive price) with prices that include time (time-inclusive price) for 2 types of home foods: home foods using basic ingredients (home recipes) vs. home foods using more processed ingredients (processed recipes). The time-inclusive and time-exclusive prices are compared to determine whether the time-exclusive prices in isolation may mislead in drawing inferences regarding the relative prices of foods.

DESIGN
We calculated the time-exclusive price and time-inclusive price of 100 home recipes and 143 processed recipes and then categorized them into 5 standard food groups: grains, proteins, vegetables, fruit, and dairy. We then examined the relation between the time-exclusive prices and the time-inclusive prices and dietary recommendations.

RESULTS
For any food group, the processed food time-inclusive price was always less than the home recipe time-inclusive price, even if the processed food's time-exclusive price was more expensive. Time-inclusive prices for home recipes were especially higher for the more time-intensive food groups, such as grains, vegetables, and fruit, which are generally underconsumed relative to the guidelines.

CONCLUSION
Focusing only on the sticker price of a food and ignoring the time cost may lead to different conclusions about relative prices and policy recommendations than when the time cost is included.