Understanding food waste through trade-off and opportunity cost concepts

​Lesson Summary

When it comes to food, consumers and producers are faced with choices.  Producers must consider how much food to produce, how to process it and how to get it to the consumer before it goes bad. For consumers, they may decide not only what to consume, but what producers to buy from and how much to purchase and consume.  Consumers must make these choices given a scarcity of time and limited budgets. 

This raises questions for economists to consider. What are the choices and trade-offs that consumes make when it comes to buying food?  What opportunity cost do consumers and producers incur to get want they want or to meet social goals of reducing food waste? Are these opportunity costs related to the amount of food wasted? What trade-offs do producers make when selecting methods of production, processing and transportation?

In this lesson

Students will:

  • Describe the environmental and food security implications of food waste
  • Identify factors contributing to food waste and loss for consumers and producers.
  • Compare the magnitude of food loss and waste between regions.
  • Evaluate the trade-offs and opportunity cost of a consumer's food choice
  • Propose tips to reduce food waste at home
  • Construct a decision-making grid for a food producer to reduce food loss.  
  • Opportunity cost: Because of scarcity, any time a choice is made there are alternatives that are not chosen. More precisely, there is always one next best alternative that is not chosen. The value of this next best alternative is the opportunity cost.
  • Trade-offs: Few choices are all-or-nothing propositions; they usually involve getting a little more of one option in exchange for a little less of something else. When making choices, people weigh the cost (what is given up) with the benefit (what is gained). 
  • Food waste: Food that is grown and intended for people to consume, but is not consumed or discarded during at the retail stage or by the consumer, is considered waste.
  • Food loss: Food that is grown and selected for the consumer that becomes unavailable for any reason during the farming, harvest, processing or distribution step it is consider.

Warm up

  • Ask students to guess what percent of the food supply is wasted each year in the United States. 
  • Compile their answers and then explain that according to the United States Department of Agriculture (USDA), 30-40% of food is wasted each year at the retail or consumer levels.
  • Ask students to identify ways that food is wasted in N. American households.
  • Follow up and ask students what choices do consumers make that contribute to food waste?
  • Explain that food waste is also tracked at a producer level and this is referred to as "food loss."
  • As the world population increases, feeding billions more people will require greater efficiencies in food production, distribution and consumption. Food loss and waste not only impact consumers, but have an impact on productive resources and food security. Explain that reducing food loss and waste is considered to be a problem for world governments and economists to solve in the grand challenge of sustainably feeding an increasing population.

Individual ActivitieS
Group Activity
  • Select a place to observe and brainstorm a way to estimate how much food is wasted by students in a given time frame.  For example, students might track the amount of food that they (themselves) throwaway during a school lunch period in a given week.  Students will create a food waste log or spreadsheet to record and determine the percent of the food that was discarded because it was spoiled, expired or "ugly" or was too large of a portion.  You may also encourage students to explore other ways to track food waste for consumers or producers.  Students can create a list of mobile apps might help.  Be sure that students consider the ethical considerations of observing and tracking food that is waste
  • Review a list of criteria that consumers use when purchasing food and groceries
  • Create a list of incentives that might encourage producers and consumers to reduce food loss / waste.  This can be done individually or in small groups.  Compile the ideas into one list and prioritize the top three.  Refer students to the Ag Econ Careers webpage.  Select the job title, Food Products Manager from the section, "Here's where a degree in Agricultural Economics could take you."  Ask them to image what challenges a Food Products Manager might foresee if these incentives were implemented.
  • Discuss what things can be done to reduce food waste at home (e.g: Plan meals ahead, Shop Smart, Check Use-by dates, Freeze left-overs, Start Composting).
World Food Prize Institute Connection
  • The World Food Prize Foundation and program partners across the United States provide high school students the opportunity through Youth Institutes to research global issues in agriculture and development and propose their own recommendations and ideas for how to solve global challenges.
  • As part of the research process in the program, students select one key factor affecting food security.
  • This lesson relates directly to these factors.
    • 6. Sustainable Agriculture
    • 8. Spoilage and Waste
    • 20. Farm to Market
  • Refer students to the Purdue Ag Econ Careers webpage.  Select the job title, Supply Chain Manager from the section, "Here's where a degree in Agricultural Economics could take you." Imagine you are a Supply Chain Manager who works for a large producer of tomatoes in Indiana.  You have been given the assignment of solving the problem to reduce their food losses before the tomatoes reach markets and consumers.  Construct a decision-making grid for food producers.  Consider the criteria and alternatives.  Include a list of incentives that might encourage producers to reduce food loss / waste.