In 2021 and 2022, something happened in most wealthy countries that hadn’t happened in a generation. Prices started rising noticeably. Not everywhere at once, not for everything equally, but across enough categories that ordinary people noticed. The petrol cost more. The groceries cost more. Rent went up. Restaurants raised their prices. Energy bills climbed. Over roughly eighteen months, the general price level in countries like Australia, the United States, the United Kingdom and most of Europe rose by somewhere between 8 and 12 per cent, depending on the country and the measure.
This was called, correctly, inflation. It was the first major inflationary episode most people under forty had lived through as adults. And it produced, alongside the genuine economic effects, an enormous amount of discussion — some of it illuminating, much of it confused — about what had caused it, what would stop it, and what it meant for ordinary lives.
Inflation is one of the topics where clear economic thinking is genuinely hard, where the confident voices you hear often disagree with each other for reasons that aren’t frivolous, and where the underlying mechanisms are more complicated than simplified accounts admit. Understanding even the basics properly takes some work. It’s worth doing, because inflation shapes wages, savings, debt, government budgets, and the balance of economic life in ways that affect almost everyone.
What inflation actually is
Inflation is a sustained increase in the general price level of an economy. The key word is sustained. One-off price jumps — a bad harvest, a supply disruption, a currency shock — aren’t inflation in the economist’s sense. They’re price spikes. Inflation is what happens when prices keep rising, month after month, year after year, across most goods and services rather than just specific ones.
This matters because it shifts the underlying question. One-off price spikes can be caused by specific events. Sustained inflation requires that something about the underlying money-and-goods balance has shifted in a way that keeps producing higher prices. The causes of sustained inflation and the causes of specific price spikes can be different, and confusing them leads to bad diagnoses.
The two main stories
There are two broad families of explanations for what causes inflation, and they’ve been in dialogue — sometimes productive, sometimes bitter — for about a century.
The monetary story. Associated most strongly with the American economist Milton Friedman, who won the Nobel Prize in 1976, this account says that sustained inflation is always, fundamentally, a monetary phenomenon. When the money supply grows faster than the economy’s capacity to produce goods and services, the excess money chases the available goods, and prices rise. Friedman’s famous claim — inflation is always and everywhere a monetary phenomenon — summarised a research programme he and his collaborator Anna Schwartz developed over decades, showing close historical correlations between money-supply growth and subsequent inflation across many countries and time periods.
The monetary story implies a specific response. If inflation is monetary, then the way to control it is through monetary policy — central banks adjusting interest rates and the money supply to bring the quantity of money back into balance with the economy’s productive capacity. This has been the dominant framework in central banking for the last forty years.
The cost and demand story. A different account, with roots going back to John Maynard Keynes and developed by subsequent economists including William Phillips (whose name attaches to the Phillips curve we’ll mention shortly) and many others, emphasises the real-economy drivers of price changes. In this framework, inflation can be driven by cost-push factors — rising input prices for producers (oil shocks, supply-chain disruptions, labour shortages pushing up wages) — and by demand-pull factors — total spending in the economy exceeding the economy’s ability to produce, so buyers bid up prices as they compete for limited goods.
Under this framework, the causes of inflation are heterogeneous, and the response depends on the cause. Cost-push inflation from an oil shock doesn’t respond well to the same treatment as demand-pull inflation from excessive government spending. Monetary policy matters, but it operates alongside many other factors, and treating inflation as purely monetary misses the actual mechanics in many real cases.
The two frameworks aren’t entirely incompatible. Most contemporary economists see them as complementary — monetary factors shape the medium-run trajectory of prices, while cost and demand factors affect short-run variations. The relative weights given to the different factors, though, continue to be genuinely contested.
The Phillips curve, and the trouble it caused
A specific framework that has shaped inflation thinking for sixty years came from the New Zealand economist William Phillips, whose 1958 paper documented an apparent relationship between unemployment and wage growth. Low unemployment seemed to be associated with higher wage growth (and thus higher inflation); high unemployment with lower wage growth. This trade-off, soon called the Phillips curve, suggested that policymakers could choose a point along it — accept some inflation to get lower unemployment, or accept some unemployment to get lower inflation.
For about a decade, this framework dominated macroeconomic policy. Then, in the 1970s, it fell apart. Many advanced economies experienced stagflation — simultaneous high unemployment and high inflation — something the simple Phillips curve said shouldn’t happen. Friedman and the American economist Edmund Phelps had predicted this breakdown in the late 1960s, arguing that the trade-off between inflation and unemployment existed only in the short run, and that over the longer term, what mattered was people’s expectations about inflation. Once workers and firms expect inflation, they build that expectation into wage demands and price-setting, which produces continued inflation even at high unemployment.
The expectations-augmented Phillips curve that came out of this debate has been the dominant framework for central banks since the 1980s. Central banks focus heavily on managing inflation expectations — keeping the public’s expected future inflation anchored at low levels — because if expectations become unanchored, inflation can become self-sustaining in ways that are very hard to reverse.
This is partly why the 2021-2022 inflation episode produced so much anxiety among economists and central bankers. The concern wasn’t just the price rises themselves. It was the risk that sustained price rises would reshape expectations, producing the kind of entrenched inflation that had been so painful to break in the late 1970s and early 1980s. As of the most recent data, expectations seem to have held reasonably well in most advanced economies — but the concern about them was a significant driver of how aggressively central banks responded.
Who inflation actually hurts
A common claim about inflation is that it’s bad for everyone. This isn’t quite right. Inflation affects different groups quite differently, and the distributional effects are often less discussed than they should be.
People on fixed incomes lose purchasing power. Retirees on fixed pensions, workers whose wages adjust slowly, anyone receiving a nominal amount that doesn’t rise with prices — all of these see the real value of their income fall during inflation. This is one of the most straightforward harms.
People with savings in nominal terms lose. Money in a bank account, government bonds paying fixed interest, any financial asset denominated in nominal currency — all lose real value as prices rise. This is why elderly savers and conservative investors are often hurt particularly badly by inflationary episodes.
People with nominal debts benefit. If you owe someone a fixed amount of money, and prices and wages rise, your debt becomes easier to pay off in real terms. Mortgage holders during inflationary periods often find their debts shrinking in real value — a substantial transfer from lenders to borrowers.
Workers with wage-bargaining power can sometimes maintain their position. Workers in strong unions, with binding contracts, or with skills that remain in demand, often see their wages rise in line with prices. Workers in weaker positions often see wages lag prices, producing real wage declines.
Governments that owe money in their own currency benefit. Government debt, denominated in the currency the government can print, becomes easier to pay off as inflation rises. This has historically created temptations for governments to use inflation as a form of debt reduction — a practice sometimes called inflation tax.
The distributional effects of inflation matter because political arguments about inflation often implicitly favour particular groups. Inflation hurts ordinary people is usually true for some ordinary people and false for others. Fighting inflation is in everyone’s interest is similarly mixed — the fight usually involves raising interest rates, which hurts borrowers and can cause unemployment, which hurts workers. There’s no policy response that’s good for everyone, and being clear about who bears the costs of each response is part of honest economic discussion.
What central banks actually do
Since the 1990s, the dominant framework for central banking in advanced economies has been inflation targeting. Central banks — the Reserve Bank of Australia, the Federal Reserve in the United States, the European Central Bank, the Bank of England, and others — are typically given a target inflation rate (usually around 2 per cent annually) and are tasked with using their policy tools to keep actual inflation close to that target over the medium run.
The main tool is the policy interest rate. When inflation is too high, the central bank raises interest rates, which makes borrowing more expensive, reduces spending and investment, and slows the economy. As the economy slows, demand falls, and upward pressure on prices eases. When inflation is too low — or the economy is weak — the central bank lowers interest rates to stimulate spending and investment.
This sounds straightforward. In practice, it’s much harder than it sounds. The relationship between interest rates and inflation operates with long and variable lags — rate changes today affect inflation one to two years from now. Central banks have to forecast future inflation based on incomplete data, adjust rates based on their forecasts, and hope that the adjustment produces the desired effect by the time it takes hold. Mistakes happen frequently. Too-aggressive tightening produces recessions. Too-loose policy allows inflation to become embedded. Getting the balance right is, in practice, deeply difficult, and looking at central banks’ historical record is a humbling exercise.
The counter-thread worth hearing
A growing body of economists argues that the conventional inflation-targeting framework has specific limitations that have become more visible in recent years.
The American economist Stephanie Kelton and other proponents of what’s called Modern Monetary Theory argue that the conventional framework overemphasises monetary policy and underemphasises fiscal policy in managing inflation. In their account, inflation is caused by real resource constraints hitting the economy — not enough workers, not enough materials, not enough capacity — and the right response is usually to address those constraints directly, through fiscal and regulatory policy, rather than to raise interest rates in a way that slows the whole economy.
This remains a minority view among professional economists, but it’s forced some useful debate about whether conventional frameworks are as well-supported as the confident central-banking discourse often suggests.
A related concern, coming from mainstream economists like Olivier Blanchard (former chief economist at the IMF), is that the 2 per cent inflation target itself may be too low given the economic conditions of the last two decades — interest rates near zero for long periods, difficulty stimulating demand, low underlying inflation pressures. Blanchard has argued that a higher target, perhaps 3 or 4 per cent, would give central banks more room to respond to shocks.
None of this means the conventional framework is wrong. It means it’s not as settled as popular discussion sometimes implies, and thoughtful economists disagree in good faith about significant features of how inflation should be managed.
What this means for ordinary life
For most readers, the practical implications of inflation for personal finance are worth understanding.
Savings and debt behave oppositely under inflation. Money saved at a fixed interest rate lower than inflation loses real value over time. Money borrowed at a fixed rate lower than inflation becomes cheaper in real terms. This has implications for how to hold wealth during different economic environments — diversification across inflation-sensitive assets (stocks, real estate, commodities in some cases) often protects against inflation better than holding cash or bonds.
Expect wages to lag prices during inflationary episodes. This is particularly relevant for workers early in their careers, whose negotiating power is often limited. The practical response is to focus on building skills that increase bargaining power over time, rather than assuming wages will automatically keep up with prices.
The headline inflation number can hide what’s actually happening to you. Your personal inflation rate depends on what you actually buy. Students renting apartments and buying a lot of groceries may experience inflation very differently from homeowners who have paid off their mortgages and drive less. Average figures obscure important variation.
Inflation affects long-term planning. A wage that looks good today may be modest in real terms in a decade. An education investment that looks expensive today may be worth much more in nominal terms by the time it pays off. Thinking in real (inflation-adjusted) rather than nominal terms is a small skill with significant long-term benefits.
The question that remains
The deepest thing to understand about inflation is that it’s a genuinely difficult problem — one where expert disagreement is substantive rather than merely political, where mechanisms operate with long lags, and where different responses benefit and harm different groups in ways that matter. The confident voices in public discussion often conceal the underlying uncertainty. The genuine experts tend to express more uncertainty than amateurs.
This doesn’t mean inflation is hopelessly mysterious. It means that forming views about it requires more care than forming views about simpler topics. Read multiple sources. Notice when someone is presenting one framework as if it were the only one. Pay attention to who benefits and who loses under specific policy responses, not just to whether the policy is technically correct. Inflation is a topic where the hard work of careful economic thinking is more valuable than the intuition the topic initially seems to invite.
The question to carry, especially if you find yourself with strong views about inflation policy:
Which framework is your view actually based on — monetary, cost-push, demand-pull, or something else — and have you considered what the other frameworks would say about the same situation?
Key research referenced: Milton Friedman and Anna Schwartz, A Monetary History of the United States (1963); John Maynard Keynes, The General Theory of Employment, Interest and Money (1936); William Phillips’s 1958 paper on wage growth and unemployment; Milton Friedman and Edmund Phelps on the expectations-augmented Phillips curve (late 1960s); Stephanie Kelton, The Deficit Myth (2020); Olivier Blanchard’s recent writing on inflation targets.