Inflation is the most misunderstood force in personal finance. It doesn't take your money — it takes what your money can buy. And it works silently, year after year, while your bank balance stays the same.
The real cost of doing nothing
French inflation has averaged about 2.1% per year since 2000. That sounds small. It isn't. Here's what happens to €100,000 over different time periods:
| Time period | Nominal value | Real purchasing power | Lost to inflation |
|---|---|---|---|
| 5 years | €100,000 | €90,000 | €10,000 |
| 10 years | €100,000 | €81,000 | €19,000 |
| 20 years | €100,000 | €65,500 | €34,500 |
| 25 years | €100,000 | €58,000 | €42,000 |
After 25 years, your €100,000 is still €100,000 in the bank. But it only buys what €58,000 would have bought when you deposited it. You lost nearly half your wealth without spending a cent.
Historical inflation shocks
The 2% average hides brutal spikes. Recent history reminds us that inflation can surge unexpectedly:
2023: 4.9% — food and services catch up
2024: 2.3% — returning toward ECB target
2025: 1.8% — below ECB 2% target
The 2022–2023 spike destroyed ~10% of purchasing power in just two years. Savings accounts paying 0.5% didn't come close to compensating.
What protects against inflation
Not all assets suffer equally. Here's how different asset classes have historically performed during inflationary periods:
| Asset class | Inflation protection | Historical real return |
|---|---|---|
| Stocks (global ETF) | Strong | ~4.5%/year after inflation |
| Real estate | Good | ~2-3%/year after inflation |
| Corporate bonds | Weak | ~0.5-1%/year after inflation |
| Government bonds | Poor | ~0-0.5%/year after inflation |
| Cash / savings account | Negative | ~-1.5 to -2%/year after inflation |
Cash is the worst place for long-term wealth. Even a high-yield savings account at 3% loses money after 2% inflation and taxes on interest. In France, interest is taxed at 30% (PFU), so your 3% becomes 2.1% after tax — barely breaking even with inflation.
The compound erosion
Inflation compounds just like investment returns — but in reverse. Over 30 years at 2.5% inflation:
- €50,000 becomes worth €23,800 in today's money
- €100,000 becomes worth €47,600 in today's money
- €500,000 becomes worth €238,000 in today's money
This is why long-term financial planning must account for inflation. A retirement target of €500,000 in 30 years is really only worth €238,000 today. You'd need about €1.05 million in 30 years to have the equivalent of €500,000 today.
Three strategies to protect yourself
1. Invest in stocks. Global equity ETFs (like MSCI World) have returned ~7% nominal over decades. After 2.5% inflation, that's 4.5% real — your money actually grows in purchasing power.
2. Consider real estate. Property values and rents tend to rise with inflation. A fixed-rate mortgage becomes cheaper in real terms over time — inflation is effectively paying down your debt.
3. Avoid long-term cash holdings. Keep 3–6 months expenses in cash for emergencies. Everything else should be invested. The "safety" of cash is an illusion — it's guaranteed to lose purchasing power.
Use the inflation erosion calculator to see exactly how much your savings will lose over time. Input your current savings, expected inflation rate, and time horizon. The tool shows you the real value in today's money — and what return rate you'd need to break even.