Real Purchasing Power6 分で読めます

100 Years of Currency Value Change

What could you buy with $1 a hundred years ago, and how many dollars would it take to buy the same thing today? The answer shows most clearly why money loses value when you simply leave it alone.

$1 in 1913 = about $34 today

The United States has produced an official Consumer Price Index (CPI) that continues to this day, starting from 1913. That is why we can track 'the value of money a century ago' fairly accurately.

Based on U.S. Bureau of Labor Statistics (BLS) data, $1 in 1913 corresponds to roughly $34 (about $33–34) of purchasing power as of 2026. Put the other way, today's $1 buys only about 3 cents' (about 3%) worth in 1913 terms. Over the past century or so, general prices rose roughly 34-fold, and cumulative inflation reached about 3,200–3,300%.

Because decimals and update timing differ across sources, it is more accurate to read this as a range like 'about 33–34x' and 'cumulative about 3,200–3,300%.'

The frighteningly quiet power of 3% a year

What is surprising is that this 34-fold increase is not the result of extreme price spikes. From 1913 until now, the average annual inflation rate in the United States has been only about 3.1–3.2%. Looking at any single year, it feels like 'just over 3%' and hardly threatening.

But once this 3% compounds for over a century, the story changes. Compounding works the same on returns and on prices. If prices rise 3% every year, they double roughly every 24 years (Rule of 72), and over 100 years those doublings stack up to more than 30-fold. This 'quiet 3% a year' is the true identity of what eats away at currency value.

Rule of 72: 72 ÷ inflation rate (%) ≈ the number of years for prices to double. At 3% a year, that is about 24 years.

What 'just leaving cash alone' really means

This history tells us that 'doing nothing' is in fact also a choice. If you had left cash in a drawer or a no-interest account for 100 years, the nominal amount would be unchanged but about 97% of its purchasing power would have disappeared.

Of course, no one invests for 100 years. But this erosion is clear even over 10- or 20-year spans. At 3% annual inflation, currency value falls to about 55% after 20 years and to about 40% after 30 years. That is why in long-term investing, 'did it beat inflation (real return)' matters as much as the 'return' itself.

In Korea, simple comparison is difficult due to war and currency reforms (1953, 1962), but there were many periods during high-growth years when inflation was far higher than in the United States.

So what should you look at

The history of currency erosion is not a story meant 'to scare you' but one that says 'set a reference point.' Whatever the asset, it must at minimum beat inflation for your money to have grown in real terms.

But the assets that try to beat inflation are not free either. Stocks have far outpaced inflation over the long run, but along the way they suffered drawdowns in the -50% range and multi-year loss periods several times, and even real assets like gold have had stretches of over a decade going nowhere. 'Beating inflation' and 'enduring volatility' always come as a set.

よくある質問

Q. Why calculate starting specifically from 1913?

Because official CPI data comparable to the method the BLS uses today exists in the United States starting from 1913. The Minneapolis Fed and others also provide inflation calculators going back to 1913. Estimates exist for earlier data too, but they are less consistent.

Q. Is rising prices always a bad thing?

Mild inflation (around 2% a year) is actually seen as a sign that the economy is running normally. The problem is not inflation itself, but when your money cannot keep up with its pace and your real purchasing power shrinks. That is why the relative view of 'does it beat inflation' is the key.