Wealth & Inequality
The Mathematical Reason the Rich Keep Getting Richer
Thomas Piketty buried a single inequality in 700 pages of data, and it may be the most unsettling formula in modern economics: r > g.
The Idea
The formula is deceptively simple. 'r' is the average annual return on capital — what your wealth earns when it's invested in stocks, property, bonds, or a business. 'g' is the rate of economic growth — how fast the overall economy expands, which broadly determines how fast wages and incomes rise. Piketty's central claim, drawn from two centuries of data across multiple countries, is that r has historically outpaced g by a significant margin. Capital tends to return somewhere between 4 and 5 percent annually over the long run. Economic growth rarely sustains above 1 to 2 percent in mature economies. The gap between those two numbers is where inequality lives and compounds. Here's why that gap matters so much. If your wealth grows faster than the economy does, then wealth — as a share of total income — will steadily concentrate among those who already have it. It isn't about anyone doing anything wrong, or any conspiracy, or even policy failure. It's closer to a gravitational law: returns on capital pull wealth upward, while wages — tied more tightly to 'g' — move more slowly. The wealthy don't need to outwork or outthink anyone. They simply need to own things that compound. What makes Piketty's argument genuinely provocative is that he treats this not as an accident of recent policy but as the historical default — a pattern interrupted only by the extraordinary disruptions of two World Wars and the policy choices that followed them.
In the World
For a vivid illustration, consider the arc of European landed aristocracy — not as a historical curiosity but as a working proof of concept. For centuries, old families didn't merely maintain their wealth; they extended it across generations with minimal effort, simply because land returned more than the economy grew. Tenants paid rents, estates appreciated, and the gap between a noble family and a skilled tradesperson widened with each passing decade, even when the tradesperson worked harder and earned more in absolute terms. Piketty points to the novels of Jane Austen and Honoré de Balzac as data, in a sense. Characters in those novels understand, with crystalline clarity, that marrying well — meaning marrying capital — is a more reliable path to security than any profession. Balzac's Père Goriot contains an explicit speech by a cynical character who walks a young man through the arithmetic: even a brilliant legal career, worked at furiously for decades, cannot match the income of simply inheriting a modest fortune invested safely. The math, Balzac's villain explains, is not close. The 20th century briefly interrupted this logic. Wars destroyed capital stocks, progressive taxation compressed returns, and strong postwar growth temporarily narrowed the gap. But by the 1980s — with lower top tax rates, rising asset prices, and slowing productivity growth — the historical pattern began reasserting itself. The Gini coefficients followed.
Why It Matters
Understanding r > g doesn't require you to share Piketty's politics or his proposed remedies — a global wealth tax that most economists consider unworkable. What it does is sharpen your lens for thinking about your own financial position and the world you're navigating. If returns on capital consistently outpace wage growth, then the single most important financial variable in a person's life isn't their salary — it's whether they own assets that compound. This reframes the common intuition that working harder or earning more is the primary engine of financial progress. Earning more matters, but what you do with what you earn matters at least as much, and possibly more over time. It also changes how you read economic news. When you hear that stock markets rose significantly while wage growth remained modest, you're watching r > g play out in real time. That's not a separate story about markets and another about wages — it's one story, and Piketty's formula is its grammar. Whether you find his conclusions alarming or overstated, the underlying mechanism is worth sitting with. Wealth compounds. Growth distributes. And those two rhythms are almost never in sync.
A Question to Ponder
If the return on capital reliably outpaces economic growth, what would have to change — in policy, culture, or individual behaviour — to make that gap work for more people rather than fewer?
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