## Consumer Budget Constraint Graph

Consumer budget constraint graph shows the combinations of goods that can be purchased by a consumer with a given level of income and given a certain set of prices. Let's take a look at Figure 1 below.

Figure 1 above shows a consumer budget constraint graph. For a given level of income \(B_1\), a consumer can purchase any combination of goods \(Q_x\) or \(Q_y\) that lie on the green budget constraint. For example, a bundle \((Q_1, Q_2)\) is attainable as a point with these coordinates lies on the budget line. This point is marked in pink in the graph above. Note that consumer spends all their income on purchasing a bundle of these two goods.

Points that lie to the right of the budget constraint are unattainable as the consumer's budget is insufficient to purchase higher quantities of both goods. Points to the left of the budget constraint are all feasible. However, as it is assumed that a consumer wants to maximize their utility, we infer that they would choose a point that lies on the budget line as they would spend all of their income and therefore get the most utility out of their budget allocation.

What happens if consumer budget changes? If consumer budget increases, then a budget constraint graph will shift in parallel to the right. If consumer budget decreases, then a budget constraint graph will shift in parallel to the left. It is more tricky to consider what happens if the prices of the two goods change. If one good becomes much cheaper, then indirectly, a consumer will be better off, even if their income is unchanged, as they will be able to consume more of this particular good.

Let's explore further with the help of Figure 2 below!

Figure 2 above shows changes in consumer budget constraint. In particular, it shows a pivotal shift in consumer budget from \(B_1\) to \(B_2\). The shift is occurring due to a decrease in the price of the good \(Q_x\). Note that a new bundle \((Q_3,Q_2)\) is now attainable.

**B****udget constraint graph** shows the combinations of goods that can be purchased by a consumer with a given level of income and given a certain set of prices.

**Want to learn more?**

**Why not check out:**

- Budget Constraint

## Budget Constraint and Indifference Curve

Budget constraint and indifference curves are always analyzed together. **Budget constraint** shows the limitation that is imposed on consumer due to their limited budget.** Indifference curves **represent consumer preferences. Let's take a look at Figure 3 below.

Figure 3 shows a budget constraint and indifference curve. Note that the bundle of choice \((Q_1, Q_2)\) lies on the budget line exactly where the indifference curve \(IC_1\) is tangent to it. The utility given a budget constraint \(B_1\) is maximized at this point. Points that lie on higher indifference curves are unattainable. Points that lie on lower indifference curves would yield lower levels of utility or satisfaction. Thus, the utility is maximized at point \((Q_1, Q_2)\). The indifference curve shows a combination of goods \(Q_x\) and \(Q_y\) that yield the same level of utility. This set of choices holds due to the axioms of revealed preference.

**Budget constraint** is the limitation that is imposed on consumer due to their limited budget.

**Indifference curves **are graphical representations of consumer preferences.

**Learn more in our articles:**

- Consumer Choice

- Consumer Preferences

- Indifference Curve

- Revealed preference

## Budget Constraint Graph Example

Let's go through an example of a budget constraint graph. Let's take a look at Figure 4 below.

Figure 4 above shows a budget constraint graph example. Imagine you can consume only two goods - hamburgers or pizzas. All your budget has to be allocated between these two particular goods. You have $90 to spend, and a pizza costs $10, while a hamburger costs $3.

If you spend all your budget on hamburgers, then you can buy 30 in total. If you spend all your budget on pizzas, then you can buy only 9. This implies that pizzas are relatively more expensive than hamburgers. However, neither of these two choices would yield a higher level of utility than the bundle that lies on \(IC_1\) as they would lie on lower indifference curves. Given your budget \(B_1\), the highest indifference curve that is attainable for you is \(IC_1\).

Thus, your choice is maximized at a point \((5,15)\), as shown in the graph above. In this consumption scenario, your chosen bundle consists of 5 pizzas and 15 hamburgers.

## Budget Constraint Slope

Let's continue our example of pizzas and hamburgers, but take a look at how your consumption would change if the slope of your budget constraint changed. Let's take a look at Figure 5 below.

Figure 5 above shows a budget constraint slope example. Imagine that there is a price change, and now a pizza costs $5 instead of $10. The price of the hamburger is still at $3. This means that, with a budget of $90, you can now get 18 pizzas. So your maximum possible consumption level of pizza increased from 9 to 18. This causes the budget constraint to pivot as its slope changes. Note that there is no change to the point \((0,30)\) as the maximum amount of hamburgers you can purchase did not change.

With your new budget line \(B_2\), a higher level of utility that lies on the \(IC_2\) indifference curve is now attainable. You can now consume a bundle at a point \((8,18)\), as shown in the graph above. In this consumption scenario, your chosen bundle consists of 8 pizzas and 18 hamburgers. How these changes between the bundles happen is guided by the income and substitution effects.

The slope of the budget line is the ratio of the prices of the two goods. The general equation for it is as follows:

\(Slope=-\frac{P_1}{P_2}\).

To learn more about the slope of the budget constraint and its other properties, why not check out:

- Budget Constraint

## Difference between Budget Constraint and Budget Line

What is the difference between budget constraint and budget line? Roughly speaking, they are the same thing. But if you really want to differentiate between the two, then there is a way!

You can think of a **budget constraint** as an inequality. This inequality must hold because you can strictly spend the amount that is less than or equal to your budget.

The budget constraint inequality is, therefore:

\(P_1 \times Q_1 + P_2 \times Q_2 \leqslant I\).

As for the **budget line**, you can think of it as a graphical representation of the budget constraint inequality. The budget line would show where this inequality is binding. Inside the budget line, there will be a **budget set**.

The general formula for the budget line:\(P_1 \times Q_1 + P_2 \times Q_2 = I\).

A **budget set** is a set of all possible consumption bundles given specific prices and a particular budget constraint.

**Like what you are reading? Dive deeper into this topic here:**

- Income and Substitution Effects

## Budget Constraint Graph - Key takeaways

**Budget constraint graph**shows the combinations of goods that can be purchased by a consumer with a given level of income and given a certain set of prices.**Budget constraint**is the limitation that is imposed on consumer due to their limited budget.**Indifference curves**are graphical representations of consumer preferences.- A
**budget set**is a set of all possible consumption bundles given specific prices and a particular budget constraint. - You can think of a
**budget constraint**as an inequality. You can think of a**budget line**as a graphical representation of the budget constraint inequality.

###### Learn with 15 Budget Constraint Graph flashcards in the free StudySmarter app

We have **14,000 flashcards** about Dynamic Landscapes.

Already have an account? Log in

##### Frequently Asked Questions about Budget Constraint Graph

How do you graph a budget constraint?

You graph a budget constraint by drawing a straight line that follows the equation:

P1 * Q1 + P2 * Q2 = I

What is a budget constraint diagram?

Budget constraint diagram shows the combinations of goods that can be purchased by a consumer with a given level of income and given a certain set of prices.

How do you find the slope of a budget constraint on a graph?

The slope of the budget constraint on a graph is the ratio of the prices of the two goods.

What determines the slope of the budget constraint?

The slope of the budget constraint is determined by the ratio of the prices of the two goods.

What is the difference between budget constraint and budget line?

You can think of a budget constraint as an inequality, whereas a budget line is a graphical representation of the budget constraint inequality.

What causes budget constraints?

Budget constraints are caused by limited incomes.

What happens to the budget constraint when income increases?

The budget constraint shifts outwards when income increases.

##### About StudySmarter

StudySmarter is a globally recognized educational technology company, offering a holistic learning platform designed for students of all ages and educational levels. Our platform provides learning support for a wide range of subjects, including STEM, Social Sciences, and Languages and also helps students to successfully master various tests and exams worldwide, such as GCSE, A Level, SAT, ACT, Abitur, and more. We offer an extensive library of learning materials, including interactive flashcards, comprehensive textbook solutions, and detailed explanations. The cutting-edge technology and tools we provide help students create their own learning materials. StudySmarter’s content is not only expert-verified but also regularly updated to ensure accuracy and relevance.

Learn more