Inflation, explained

In the last lesson we mentioned inflation a few times. It sounds technical, but it is the simplest force in finance. The same dollar buys less stuff next year than it does today.

Inflation is a quiet tax. You do not see it on your bank statement, nobody sends you a bill, but it slowly drains the buying power of every dollar you do not put to work. Understanding how it operates is the difference between feeling like you are saving and actually getting somewhere.

A loaf of bread, fifty years apart

In 1975, a loaf of bread cost about 30 cents. Today the same loaf is around $4. The bread has not gotten ten times better. It is the same wheat, the same recipe, often the same brand. What changed is the value of the dollar.

This is what inflation means in practice: the prices of the things you actually buy creep up year after year. The exact rate varies, but in most developed countries the long-run average is somewhere between 2 and 4 percent annually. That sounds small, but compounded over decades it is enormous.

Why does it happen?

There are two main forces. The first is the supply of money. When central banks print more dollars (or euros, or yen), each individual dollar becomes a smaller slice of a larger pie. More dollars chasing the same goods means each dollar is worth a little less.

The second is supply and demand for actual things. When demand for goods and services outpaces what the economy can produce, prices rise. Energy crises, supply chain breakdowns, wars, and labor shortages all push prices up the same way.

In normal times, central banks try to keep inflation around 2 percent. That number is somewhat arbitrary, but the idea is that mild, predictable inflation encourages spending and investing rather than hoarding cash. Hoarders lose; participants win. That is by design.

What this means for you

The most important consequence: cash sitting still is losing value every single day. If your savings account earns 0.5 percent and inflation runs at 3 percent, you are losing 2.5 percent of your purchasing power per year, even though the headline balance is technically growing.

After ten years of that, $10,000 in cash will buy roughly what $7,800 buys today. After thirty years, less than half. The longer you keep money in cash, the more of it inflation quietly eats.

This is the single best argument for investing. You do not invest because you want to "beat the market" or get rich quick. You invest because doing nothing has a cost, and that cost grows every year you ignore it.

When inflation goes wild

In normal years, 2 to 4 percent inflation is background noise. But in some times and places, it gets out of control. Hyperinflation is what happens when prices double in months instead of decades.

• Weimar Germany (1923): a loaf of bread cost 250 marks in January and 200 billion marks by November.
• Zimbabwe (2008): the central bank issued a 100 trillion dollar note. It was worth about $40 USD when printed.
• Venezuela (2018 to 2019): prices rose roughly 1.7 million percent in a single year. People shopped with stacks of bills.
• Argentina (recent years): inflation peaked above 200 percent annually and has been running in the high double digits, which is why many Argentinians hold dollars or crypto rather than pesos.

These extreme cases are rare, but they show what money can become when trust in it breaks. They are also why people in unstable economies tend to be far more financially literate than people in stable ones. When holding cash is obviously dangerous, you learn fast.

Inflation is taxation without legislation.

Milton Friedman

In the next lesson we will look at one of the main tools investors use to outpace inflation: stocks and bonds, and the difference between them.