Headlines about a recession, a boom, or a country's economic performance often lead with one figure: the growth rate. It is how economists, investors, and policymakers turn the broad question of economic performance into a number that can be tracked and compared. Yet the same percentage can mean very different things depending on how it is measured and what lies beneath it.
The question of what drives growth, and what makes it last, has occupied generations of economists. Nobel laureates such as Paul M. Romer and Daron Acemoglu have spent decades examining why some economies sustain higher growth rates while others stall, work that continues to shape how the headline number is interpreted today.
What is the economic growth rate?
The economic growth rate measures how much an economy's total output of goods and services changes from one period to another, usually expressed as a percentage change in gross domestic product (GDP).¹ It is one of the clearest signals of whether an economy is expanding, stagnating, or contracting.
Beyond how the figure is read, there's the deeper question of what drives it. Romer, whose work on endogenous growth theory placed ideas and innovation at the center of economic progress, examined why some countries sustain prosperity over decades while others fall behind.² This focus on long-run dynamics shaped his 2018 Nobel Prize and underscored a broader point: understanding what keeps growth going is one of the central questions in economics.³
What is the current global economic growth rate?
According to the IMF's April 2026 World Economic Outlook, global real GDP growth is projected at 3.1% in 2026 and 3.2% in 2027, a pace the IMF describes as "below recent outcomes and well under pre-pandemic averages".⁴ The report sets the outlook against the backdrop of the war in the Middle East and notes that the slowdown weighs most heavily on emerging markets and developing economies, especially those that import commodities and entered the year already vulnerable.⁴
Advanced economies as a group are projected to grow at 1.8% in 2026, though the picture varies. The United States is forecast at 2.3%, while the United Kingdom, Japan, and the largest euro area economies (Germany, France, and Italy) sit closer to 1% or below.⁴ Emerging market and developing economies are projected to expand at 3.9%, with India among the fastest-growing major economies at 6.5%.⁴
How is the economic growth rate calculated?
The arithmetic behind the growth rate is straightforward. What varies is which version of output you plug in, and over what time horizon you measure it.
1. Basic growth rate formula
The most direct way to measure growth is to compare output across two periods:
Growth rate = ((GDP₂ − GDP₁) / GDP₁) × 100
GDP₁ is the earlier value and GDP₂ the later one. This captures the percentage change from one period to the next and is the headline number reported each quarter or year, the starting point for every other variant.¹
2. Real GDP growth
The formula above can be applied to either nominal GDP, which uses current prices, or real GDP, which strips out the effect of price changes.⁵ Without that adjustment, growth can look positive simply because prices have risen.¹ This is why real GDP, not nominal, is the standard basis for tracking how an economy's output actually changes from one period to the next.
3. GDP per capita growth
The same formula can also be applied to GDP divided by population, giving GDP per capita.⁶ This shifts the perspective from the size of the economy as a whole to output per person, which can matter in countries where population is growing or shrinking quickly.
4. Compound annual growth rate (CAGR)
For longer time horizons, the compound annual growth rate (CAGR) gives the average annual rate of growth between a starting and ending value, factoring in compounding along the way:
CAGR = (GDPₙ / GDP₀)^(1/n) − 1
CAGR assumes a constant rate of growth across the full period, which makes it useful for comparing performance over multiple years but also means it averages out year-to-year volatility rather than reflecting it.⁷
What is a “good” economic growth rate?
There is no universal answer to what counts as a good growth rate. What looks healthy depends on a country's stage of development, demographic trends, and the quality of the growth itself, rather than only its size.
Growth varies by stage of development
Advanced economies typically grow more slowly than emerging ones, with the IMF's April 2026 World Economic Outlook projecting advanced economies at 1.8% in 2026 and emerging market and developing economies at 3.9%.⁴ The gap reflects structural differences: emerging economies often have more room to expand from a lower starting base, while advanced economies face slower population growth and operate closer to the technological frontier. But faster headline rates are not automatic. Paul Romer's endogenous growth framework argues that sustained growth depends on deliberate investment in research, ideas, and human capital, and that a large population alone is not enough to generate it.²
Quality matters as much as the headline rate
Where Romer's framework centers on what drives growth, Daron Acemoglu's centers on what determines whether it lasts. Alongside Simon Johnson and James A. Robinson, he won the 2024 Nobel Prize in Economic Sciences for research on how institutions shape national prosperity.⁸ Their argument is that sustained growth requires inclusive institutions: ones that protect property rights across a wide population, create conditions that encourage investment, and open economic opportunity to most of society.⁹ Extractive institutions, where most people lack legal protection and secure property rights, and power is held by a small ruling group, can deliver gains in the near term but tend to stall over longer horizons.⁹
For policymakers and investors, this means reading growth figures alongside measures like productivity, inequality, debt, and institutional quality. A high headline rate does not always signal durable growth, and a slower rate underpinned by stable institutions and rising productivity may matter more over time.
Final thoughts: reading the number in context
The economic growth rate is a deceptively simple figure that compresses an enormous amount of information about production, productivity, and policy into a single percentage. It remains one of the most closely watched figures in economic analysis, though the interpretation of any given number depends on the country, the time horizon, and the conditions that produced it.
Headline growth tells us that an economy expanded. Whether that expansion will last, and whether it will reach most of society, depends on innovation, institutions, and the quality of the foundations beneath it. This is the deeper question that Romer, Acemoglu, and many other economists have spent careers exploring.
To explore Paul M. Romer, Daron Acemoglu's, and other Nobel-recognized ideas in economic growth, visit UBS Nobel Perspectives & Economic Views for insights from Nobel laureates across the field.
References
- Chen J. Understanding Economic Growth Rate: Definition, Formula, and Key Examples. Investopedia, 2026.
- Romer PM. Endogenous Technological Change. Journal of Political Economy, 1990.
- Nobel Prize Outreach. Press release. NobelPrize.org, 2018.
- International Monetary Fund. World Economic Outlook: Global Economy in the Shadow of War. IMF, 2026.
- Organisation for Economic Co-operation and Development. Real Gross Domestic Product (GDP). OECD Data.
- World Bank. GDP per capita growth (annual %): Metadata. World Bank DataBank.
- Corporate Finance Institute. What is CAGR?. Corporate Finance Institute, 2020.
- Nobel Prize Outreach. Press release. NobelPrize.org, 2024.
- Nobel Prize Outreach. Advanced information. NobelPrize.org, 2024.