Course → Unit 5: Macroeconomics for Investors → Lesson 5.2

Inflation

A 6% return on your investments sounds great — until you realise prices rose 4% that year, which means your money actually only grew richer by a much smaller amount than the headline number suggests, and understanding that gap is essential to judging whether any investment is actually working for you.

What inflation is: too much money chasing too few goods

Inflation is a sustained rise in the general level of prices across an economy, meaning each dollar buys progressively less over time. A simple way to picture the underlying cause is the phrase "too much money chasing too few goods" — if the amount of money circulating in an economy grows faster than the supply of goods and services available to buy, there's more spending power competing for the same stuff, and prices get bid upward. Inflation can also be driven from the supply side: if the cost of producing goods rises sharply (say, oil prices spike, making transport and manufacturing more expensive everywhere), businesses pass those higher costs on to consumers as higher prices.

CPI and how it's measured

Inflation is tracked using the Consumer Price Index (CPI) — a measure of the average change in prices paid by households for a fixed "basket" of representative goods and services: things like food, housing, transport, healthcare, and utilities. Statisticians track the prices of this basket every month; the percentage change in the total cost of the basket compared to a year earlier is the headline inflation rate you see reported in the news. In Singapore, this is compiled and published by the Department of Statistics; in the US, by the Bureau of Labor Statistics.

CPI isn't perfect — the basket has to be updated periodically as spending habits change, and it can't capture every individual's personal experience of price changes, since a student's spending basket looks very different from a retiree's. But it's the standard, widely comparable benchmark used by governments, central banks, and investors everywhere.

Good inflation vs bad inflation

Not all inflation is bad news. A small, steady rate of inflation — most central banks target around 2% a year — is actually considered healthy: it reflects a growing economy with rising demand, gently encourages people to spend and invest rather than hoard cash, and gives businesses room to raise wages. Problems start when inflation runs too hot (rapidly rising prices erode purchasing power faster than incomes can keep up, and uncertainty makes it hard for businesses to plan) or when it runs negative — a condition called deflation, where prices actually fall, which sounds nice for shoppers but can be economically damaging, since it encourages people to delay spending (why buy today if it'll be cheaper next month?), which slows the whole economy down.

Real vs nominal returns: how inflation erodes what you earn

This is the concept every investor needs to internalise. The nominal return is the percentage gain on an investment before accounting for inflation — the number your brokerage statement shows you. The real return is what's left after subtracting inflation — the actual increase in what your money can buy. A quick approximation is simply to subtract:

If your investments return exactly the same as inflation, your real return is roughly zero — your money grew in dollar terms, but its purchasing power stayed flat. If inflation outpaces your nominal return, your real return is negative: you're losing purchasing power even while your account balance goes up. This is precisely why keeping large amounts of cash in a bank account paying little to no interest is not "safe" in real terms — inflation quietly erodes its value every year, even though the number on the screen never goes down.

Winners and losers from high inflation

High inflation doesn't hurt everyone equally. Borrowers with fixed-rate debt tend to benefit, since they repay their loans in the future with dollars that are worth less than when they borrowed them — effectively shrinking the real value of their debt. Owners of real assets — property, commodities, infrastructure — often see the value of those assets rise alongside prices generally, since real assets are, by nature, harder to "print more of." Companies with strong pricing power (think of luxury or essential-goods brands that can raise prices without losing customers) can pass rising costs onto customers and protect their margins.

Losers include savers holding cash or fixed-rate bonds, whose fixed future payments are worth less in real terms as prices rise (recall the inverse relationship you learned in Unit 4 — rising inflation typically pushes interest rates up, which pushes existing bond prices down). Fixed-income earners like retirees on a fixed pension, and any business without pricing power that gets squeezed between rising costs and customers who won't tolerate higher prices, also tend to suffer.