Suppose your friend is indifferent to the bundles $(5, 6)$ and $(6, 6)$. Are the preferences of your friend monotonic?

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> [!TLDR]
> Monotonic preferences require that more of at least one good (with no less of the other) is strictly preferred. Since your friend is indifferent between $(5,6)$ and $(6,6)$ — bundles where the second has strictly more of one good — the preferences violate monotonicity.

## Understanding Monotonic Preferences

Monotonicity is one of the foundational assumptions about rational consumer behavior. It captures a simple intuition: if you give someone more of something they value (or at least don't dislike), without taking anything else away, they should be better off — or at the very least, no worse off.

Formally, preferences are **monotonic** if whenever bundle $A$ contains at least as much of every good as bundle $B$, *and* strictly more of at least one good, then the consumer strictly prefers $A$ to $B$. In symbols, if $A = (x_1^A, x_2^A)$ and $B = (x_1^B, x_2^B)$ with $x_1^A \geq x_1^B$, $x_2^A \geq x_2^B$, and at least one inequality strict, then $A \succ B$ (A is strictly preferred to B).

The economic reasoning is straightforward: goods are desirable. A consumer who obeys monotonicity never throws away free goods; more is always weakly better, and strictly more of something (holding everything else constant) is strictly better.

## Applying the Test to Your Friend's Preferences

Now look at the two bundles your friend is considering:

- Bundle $B_1 = (5, 6)$: 5 units of good 1, 6 units of good 2  
- Bundle $B_2 = (6, 6)$: 6 units of good 1, 6 units of good 2

Compare them component by component. Bundle $B_2$ has **one more unit of good 1** than $B_1$ (6 versus 5), while the quantity of good 2 is identical in both (6 units). So $B_2$ contains everything $B_1$ has, plus an extra unit of good 1.

If your friend's preferences were monotonic, she should strictly prefer $B_2$ to $B_1$ — after all, she's getting more of good 1 at no cost to good 2. But the question tells us she is **indifferent** between the two bundles: $(5,6) \sim (6,6)$. She views them as

Q.Suppose your friend is indifferent to the bundles $(5, 6)$ and $(6, 6)$ . Are the preferences of your friend monotonic?

Concept understanding — Monotonic Preferences

Monotonic Preferences – The "More is Better" Rule

The Everyday Intuition

The Precise Definition (NCERT Class 12, Microeconomics)

What It Is NOT

Why It Matters in Economics

Understanding Monotonic Preferences

Applying the Test to Your Friend's Preferences

Q.Suppose your friend is indifferent to the bundles (5,6)(5, 6)(5,6) and (6,6)(6, 6)(6,6). Are the preferences of your friend monotonic?

Understanding Monotonic Preferences

Applying the Test to Your Friend's Preferences

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Q.Suppose your friend is indifferent to the bundles $(5, 6)$ and $(6, 6)$ . Are the preferences of your friend monotonic?

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