Inaugurated by IN-SPACe
ISRO Registered Space Tutor
S7-SA1-0280
What is the Concept of Marginal Propensity to Save?
Grade Level:
Class 12
AI/ML, Physics, Biotechnology, FinTech, EVs, Space Technology, Climate Science, Blockchain, Medicine, Engineering, Law, Economics
Definition
What is it?
Marginal Propensity to Save (MPS) is a concept in economics that tells us how much of an extra rupee earned by someone is saved, rather than spent. It measures the change in saving when income changes. If you get an unexpected bonus, MPS shows what fraction of that bonus you put aside.
Simple Example
Quick Example
Imagine your family gets an unexpected bonus of Rs. 1,000 from your father's company. If your family decides to save Rs. 300 out of that extra Rs. 1,000 and spend the rest, their MPS would be 0.3 (or 30%). This means for every extra rupee, 30 paise are saved.
Worked Example
Step-by-Step
Let's say a person's income increases. We want to find their MPS.
Step 1: Identify the initial income and initial savings.
Initial Income = Rs. 20,000
Initial Savings = Rs. 4,000
---
Step 2: Identify the new income and new savings after an increase.
New Income = Rs. 25,000
New Savings = Rs. 6,000
---
Step 3: Calculate the change in income (Delta Y).
Change in Income (Delta Y) = New Income - Initial Income
Delta Y = Rs. 25,000 - Rs. 20,000 = Rs. 5,000
---
Step 4: Calculate the change in savings (Delta S).
Change in Savings (Delta S) = New Savings - Initial Savings
Delta S = Rs. 6,000 - Rs. 4,000 = Rs. 2,000
---
Step 5: Apply the MPS formula: MPS = Delta S / Delta Y.
MPS = Rs. 2,000 / Rs. 5,000
---
Step 6: Calculate the MPS.
MPS = 0.4
Answer: The Marginal Propensity to Save (MPS) is 0.4.
Why It Matters
Understanding MPS helps governments and businesses predict how people will react to changes in income, like tax cuts or job growth. Financial analysts use it to forecast economic trends, and even AI/ML models in FinTech use such economic indicators to predict market behavior. Learning this can open doors to careers in economics, finance, or even data science.
Common Mistakes
MISTAKE: Confusing MPS with Average Propensity to Save (APS). | CORRECTION: MPS looks at the *change* in savings from a *change* in income, while APS looks at total savings divided by total income.
MISTAKE: Expressing MPS as a percentage without converting the decimal. | CORRECTION: MPS is usually expressed as a decimal (e.g., 0.25), though it can be stated as a percentage (25%) if specified. Always calculate as a decimal first.
MISTAKE: Using the change in consumption instead of change in savings. | CORRECTION: Remember MPS specifically deals with savings. If you have change in consumption, you're likely calculating Marginal Propensity to Consume (MPC).
Practice Questions
Try It Yourself
QUESTION: If a person's income increases by Rs. 800 and their savings increase by Rs. 200, what is their MPS? | ANSWER: 0.25
QUESTION: A small business owner's monthly income rises from Rs. 40,000 to Rs. 45,000. If their savings increase from Rs. 5,000 to Rs. 7,500, calculate their MPS. | ANSWER: 0.5
QUESTION: An engineer gets a salary hike of Rs. 10,000 per month. If her Marginal Propensity to Consume (MPC) is 0.7, what will be her increase in monthly savings? (Hint: MPS + MPC = 1) | ANSWER: Rs. 3,000
MCQ
Quick Quiz
Which of the following best describes Marginal Propensity to Save (MPS)?
Total savings divided by total income
The proportion of an additional rupee of income that is saved
The proportion of an additional rupee of income that is spent
Total consumption divided by total income
The Correct Answer Is:
B
MPS specifically measures the fraction of any *extra* income that is saved. Option A describes Average Propensity to Save (APS), while Option C describes Marginal Propensity to Consume (MPC).
Real World Connection
In the Real World
Government economists in India use concepts like MPS to understand how new policies, like a tax rebate or an increase in minimum wage, might affect household savings and overall economic growth. This helps them decide if a policy will encourage people to save more for their future or spend more to boost the economy. For example, if the government wants to encourage more savings for retirement, they might introduce schemes that appeal to a higher MPS.
Key Vocabulary
Key Terms
MARGINAL: referring to an additional unit or change | PROPENSITY: a natural tendency or inclination | SAVINGS: the part of income not spent on consumption | INCOME: money received, especially on a regular basis, for work or through investments
What's Next
What to Learn Next
Great job learning about MPS! Next, you should explore the concept of Marginal Propensity to Consume (MPC). MPS and MPC are closely related, and understanding both will give you a complete picture of how changes in income affect both saving and spending in an economy.
