Consumer Choice

Consumer Choice Definition

The consumer choice definition that is widely accepted in economics is one that hypothesizes why people make the consumption choices that they do when they are faced with trade-offs. A trade-off is an option that you forgo if you make a different choice. The theory of consumer choice attempts to understand why consumers choose one good or experience over another, working versus leisure, or saving versus spending their money.

If you choose to spend more money on one good, then you cannot buy as much of another good. If you want to enjoy more leisure time, you give up the time you could be working and making more money for the future. If a consumer decides to spend more of their income now, they will have less money to spend in the future. If they receive a raise at work, their budget will change.

The idea of consumer choice relies on the fact that people will make rational decisions to satisfy their wants. People want to make the choice that best fits their budget, their preferences, and optimizes the amount of pleasure they will get from their choices.

Of course, to make these choices, consumers need some bits of information. The price of a good is an important factor in a consumer's decision-making about how they can gain the most satisfaction based on their budget and their preferences. If the price of a good is too high then the consumer will buy less of it, or they will buy another lower-priced good if they are unwilling to make the trade-off.

Consumer choice theory helps us understand a consumer's behavior that results from the combination of their income and preferences. Having a clear understanding of this behavior is necessary to be able to construct the demand curve and set the price of a good appropriately.

Consumer Choice Assumptions

Let's examine some of the main consumer choice assumptions:

• Consumers are faced with budget constraints.
• Consumers have tastes and preferences that impact their choices.
• Consumers will look to optimize their decisions based on their budget and preferences.

These assumptions together operate under the traditional economic assumption that consumers will make rational choices in the hope of maximizing personal benefit.

The Budget Constraint

The budget constraint is an economist's way of saying what the consumer can afford. By assuming that there is a budget constraint we imply that people want to spend more than they have, but their budget constraint forces them to consume less than they want to. When a consumer is on a budget, they have a set amount of money to spend so they must choose between the goods they want to spend it on.

Fig. 1 - Consumer's Budget Constraint

Figure 1 above shows the consumer's budget line. As in Table 1, the consumer has several options to choose from, so long as they fit the budget line. Points A and B on the graph are viable options, whereas point C is not since it is above the budget line.

Preferences and Marginal Utility

A consumer will not just buy whatever fits their budget, that would likely not be satisfactory. They will make a choice that satisfies their preferences. A consumer's preferences are what they will choose to spend their time and money on if given the choice. A consumer's choice relies on a combination of their budget and what they prefer. Sometimes, there are choices that the consumer equally prefers, that is, they are indifferent to the choice. Much like a budget constraint, the indifference curve shows the different combinations of goods that will be equally satisfying for the consumer.

Fig. 2 - Indifference Curves

Figure 2 above shows a consumer indifference curve for the choice between burgers and fries. Points A, B, and C are all located on the same curve, indicating that they are all equally satisfying choices. Point D is located on a higher indifference curve. On I₃, the consumer can have more of both goods, which we assume is always preferred to less. I₁ offers the least amount of both goods so it is always less preferable.

Another way to describe a consumer's preference is by how much utility they receive. Utility is used to measure the level of satisfaction, or happiness, that a good provides. All points on the same indifference curve provide equal utility. Marginal utility is the additional utility that each additional unit of a good provides the consumer. When marginal utility equals zero, we have reached the maximum amount of satisfaction a good can provide.

Optimization

Once the consumer has reconciled their budget with their preferences, they will make the optimal choice. This is the choice where the budget is tangent to the highest indifference curve. In Figure 3 below, it is point A.

Fig. 3 - Optimal Consumer Choice

The highest indifference curve that the budget line is tangent to is I₂ at point A, indicating that this is where the consumer gets the highest amount of satisfaction within their budget. It also intersects point E, but this point is located on a lower indifference curve, making it less preferable overall.

Consumer Choice and Demand

Consumer choice and demand are related in that the consumer's indifference curves help to determine the demand curve for a good. If we observe how the consumer's choice changes as the price of the good rises or falls, we can figure out what the demand curve for the good itself will look like.

Fig. 4 - Consumer's Optimum Budget

Figure 4 above shows us what happens to the consumer's budget line when the price of nachos decreases. The purchasing power of the consumer's budget expands because the consumer can now buy more nachos and still buy M&Ms. If they had wanted to buy four orders of nachos at $6, they could not have bought any M&Ms, but with the reduced price they can buy four orders of nachos and four bags of M&Ms. Now, let's see what this says about the demand curve for nachos.

Fig. 5 - Demand Curve for Nachos

Figure 5 combines the two prices of nachos and the quantity demanded at each price to form the demand curve for nachos.

Model of consumer choice: Consumer Choice Theory Importance

The importance of consumer choice theory as a model of consumer choice lies in its ability to predict the consumption patterns the economy will face. Understanding what drives a consumer to make the choices that they do is important for explaining the overall shape of the economy. Consumer demand is a driving factor for an economy without which money would not flow. The demand curve represents the inverse relationship between the price of a good and the quantity a consumer demands at that price.

Using the consumer choice theory to understand the consumer's demand allows businesses to decide how to maximize profits and best allocate their resources. Understanding consumer demand and how it relates to the individual's budget also helps businesses price their goods most advantageously.

When calculating Gross Domestic Product (GDP), one of the largest sectors included is consumer spending. In 2021, consumer spending accounted for nearly $16 trillion of the $23 trillion of the US nominal GDP.¹ It is important that businesses, policymakers, and economists have an understanding of why consumers make the choices that they do to have a chance at understanding the flow of the economy and how to make business and policy choices that benefit both consumers and producers.

Consumer Choice Theory Implications

Some consumer choice theory implications are that consumers make choices that will bring them the most satisfaction that their budget allows and that consumers will face trade-offs that impact their utility. If a consumer buys more of good A they must buy less of good B. If they choose to have more leisure time, they will work less and probably reduce their income.

They can choose to either spend their money now and have less in the future or they can save it now to have more in the future. Of course, there is more that goes into these choices than just the consumer's whim. Before consumers make their choices, they typically take into account the level of risk they are willing to accept, how high their income is, what the current interest rate is, etc.

Consumer choice theory is an economist's effort to perform an economic analysis using explicit values, to model human psychological and emotional choices with implicit values. Because consumer choice theory is a model representing human behavior, there are exceptions to its application in real life. In economics, we assume that people behave rationally, but we know that is not always the case, which is one prominent criticism of consumer choice theory.

Consumer Choice Examples

Let's look at a couple of consumer choice examples. Since there are so many choices and unique preferences that seem rational to one but not another, for the sake of explaining consumer choice theory, that's okay.

Consumer choice can help economists predict how Buddy and Marge will respond to their individual situations given that they behave rationally.