Savings and Basic Economics
Savings and basic economics examines how households save, how inflation changes the value of money and how demand and supply set prices. BFSI questions apply these ideas to deposits, loans and investment choices.
Core concepts
- Savings is income not consumed; it funds emergencies and investment.
- Inflation reduces purchasing power. Real interest ≈ nominal interest − inflation.
- Compounding grows money faster over time; the Rule of 72 estimates doubling years as 72 ÷ annual return.
- Opportunity cost is the next-best alternative forgone.
- Interest is the price of money; demand and supply in the loanable-funds market influence it.
- Common instruments: savings account, fixed deposit, recurring deposit, PPF, post-office schemes and gold.
Worked example
A fixed deposit pays 8% nominal interest, inflation is 6% and interest is taxed at 20%. Post-tax nominal return = 8% × (1 − 0.20) = 6.4%. Real return ≈ 6.4% − 6% = 0.4%. Reasoning: the depositor’s purchasing power barely grows, even though the headline rate looks attractive.
Traps that cost marks
- Comparing pre-tax returns with post-tax returns.
- Ignoring lock-in, liquidity and premature-withdrawal penalties.
- Assuming all savings instruments are risk-free in real terms.
- Confusing nominal wage growth with real income growth.