Journal · Economics

Equity vs equality: the difference, explained with pizza

Equality is a rule anyone can follow without asking a question. Equity has to ask. Four people and one pizza show the difference, and a toy you can play with shows why which one grows the pie depends on what it costs to move a slice.

Highland Willow · Boone, North Carolina · 1 November 2026

Four people share a pizza every Friday. It comes cut into eight slices. The obvious answer is two each, and that answer has a name: equality. Everyone gets the same, and nobody has to explain anything.

Now the details. Ari paid the most and ate a late lunch. Dee worked a double shift, skipped lunch and paid the least. Two slices each leaves Dee 67% full, and leaves half a slice uneaten on Ari’s plate and another half on Cam’s. Cutting each slice to what each person needs feeds everyone and wastes nothing. That is equity, in the sense most people mean it.

So the short answer: equality gives everyone the same share; equity gives each person what they need, which can mean different shares, so that everyone has a fair chance. The longer answer is about what each one costs. It gets more interesting once the pizza has to grow, and sharper again once the table seats 8.3 billion people: is the world’s pizza too small, or just cut unevenly?

Equality is a rule. Equity is a judgement

Look at what each cut needs to know. Two slices each needs nothing: count the people, divide. Cutting by need needs someone to know who is hungry, someone to decide, and everyone to trust the answer. Dee may really be starving. Dee may also have noticed that saying so gets more pizza.

You may know the picture this argument usually comes with: three people of different heights watching a ball game over a fence, standing on boxes. In one panel each has one box. In the other, the boxes go to whoever needs them to see. Craig Froehle put the first version together in December 2012, from a photo of a ballpark, a stock crate and some clip art, to argue that equal opportunity was not enough on its own. The labels “equality” and “equity” were added by other people as it spread, and the drawing most people know is a 2016 redraw by the artist Angus Maguire for the Interaction Institute for Social Change.

The pizza is our version, and it shows one thing the fence hides: the boxes in the picture are free, and slices are not. Every slice Dee gets is a slice somebody else does not.

The word equity means two different things

In the fence picture, equity means according to need. In the research on fairness, the word usually means something else: in proportion to what you put in. The psychologist J. Stacy Adams built equity theory, in 1963 and 1965, on the idea that people compare what they get out against what they put in, and against the same ratio for everyone around them. A decade later Morton Deutsch argued that equity is only one of several values a sense of justice can rest on, set equity, equality and need side by side, and asked what makes a group pick one over the others.

That older equity is the first pizza in the picture. Ari chipped in 40% and gets 3.2 slices, 1.7 more than Ari can eat. Dee chipped in 10% and gets 0.8. Nobody can call that unfair to Ari. It is hard on Dee.

And in business, equity means ownership: your share of the pizzeria, not of the pizza. When two people argue about equity, it is worth checking which of the three they mean, because a good share of those arguments are about the word.

Now let the pizza grow

Economic growth, in pizza, is next Friday’s pizza being bigger than this one. In our toy, next Friday’s pizza is bought with what the four of them chip in, and people chip in more when they were fed and when they kept what they put in. If nothing gets in the way it grows 10% a week, which after 10 Fridays makes it 2.59× the size of today’s.

The argument economists have is whether the way you slice today changes how big the pizza is next week. The toy has three knobs, one for each thing that argument turns on:

• The leak. In 1975 the economist Arthur Okun described moving money from rich to poor as carrying it in a leaky bucket: some disappears on the way, to the cost of running the programmes and to weaker incentives for rich and poor alike. In the toy, a share of every moved slice falls on the floor, and the people it came from chip in a little less next week.
• The hunger cost. Someone left hungry this week chips in less next week. The OECD’s version of this, from a 2014 study we come back to below, is that people from poorer backgrounds invest less in education, which holds back what they can do later.
• The cost of asking. Slicing by need means finding out who is hungry, on top of the cost of moving slices at all, and that takes time and forms and somebody’s judgement. The same slice for everyone asks nothing. In the toy, nor does keeping what you chipped in, though in real life someone has to count what each person put in.

Where the toy starts is our choice, not a measurement, and the verdict there is close. With a 5% leak, a 50% hunger cost and 2% spent asking, the same slice for everyone grows the pizza to 1.96×, against 1.81× for slicing by need. Make asking cost 1% instead and slicing by need wins, 2.00× to 1.96×. Treat the winner at any one setting that way.

Four things the toy shows, if you play with it for a minute:

1. With no leak, no hunger cost and asking free, the slicing does not matter. All three rules grow the pizza to the same 2.59×. The whole argument about growth lives in those knobs.
2. Hunger alone favours slicing by need. Set the leak and the cost of asking to zero and the hunger cost to 50%, and slicing by need grows the pizza to 2.59×, the same slice for everyone to 2.19× and keeping what you chipped in to 1.79×.
3. Leak alone favours keeping what you put in. A 20% leak with no hunger cost and asking free turns the order round: 2.59× for keeping what you chipped in, 1.72× for the same slice and 1.47× for slicing by need.
4. Equality wins only when asking costs something. With asking free, the same slice for everyone wins nowhere on the map: it moves slices to Cam, who was already full, and pays the leak on them for nothing. Give asking a 2% cost and equality wins a band in the middle, 127 of the 651 settings on the map. That band is the case for equality: it is the rule that needs no information.

What the research says

Nobody has measured these three knobs as such, and no study we know of sets slicing by need against the same slice for everyone. What economists have measured is how inequality, and the taxes and transfers that reduce it, go with growth in real economies. Each finding speaks loosely to one of the knobs, and they point in different directions.

Okun treated the leak as real and the trade-off as a matter of values: how much leak you would put up with to move a dollar says how much you care about equality. He answered his own question. In his example, a tax on the richest 5% of families pays for a grant of $1,000 to each family in the poorest 20%, and he said he would stop at a leak of 60%: forty cents arriving for every dollar taken.

IMF economists looked across countries in 2014. Jonathan Ostry, Andrew Berg and Charalambos Tsangarides found that lower inequality, measured after taxes and transfers, went with faster and longer-lasting growth, and that redistribution itself looked mostly harmless to growth, except at the extreme. An earlier IMF note by Berg and Ostry, in 2011, found that spells of growth lasted longer in more equal countries. In their estimates, a country at the middle of their sample, with a Gini index of 40, that became as equal as a Gini of 37 could expect its growth spells to last half as long again.

The OECD, in a 2014 study by Federico Cingano, estimated that a rise in inequality of 3 Gini points, about the average rise across OECD countries over the two decades before the study, would take 0.35 percentage points a year off growth for 25 years, leaving the economy 8.5% smaller at the end. That is a projection from the model, not a measured loss. What mattered most was the gap between lower-income households and everyone else, and one key channel was the one the hunger knob stands for: people from poorer backgrounds investing less in education.

Kristin Forbes, in 2000, compared each country with itself over time, instead of comparing countries with each other, and found the opposite in the short to medium run: a rise in a country’s inequality went with faster growth in the years after. Robert Barro, the same year, found little relation overall, with inequality tending to slow growth in poorer countries and to go with faster growth in richer ones. In a 1999 working paper with the same finding, he read the richer-country result as a sign that redistribution there costs some growth: Okun’s trade-off, inferred from the pattern rather than measured as a leak.

None of these studies can say whether the same slice for everyone or slicing by need grows the pizza faster. They compare more unequal economies with less unequal ones, and the same slice for everyone is the most equal cut there is. What they do show is that the answer has moved with the sample, the period and the method: across countries and over decades, lower inequality has tended to go with faster growth; within one country over a few years, sometimes with slower. The toy can be set to give either answer, which is all it can say about the real argument.

Is there enough pizza for everyone?

Now take the table from four people to 8.3 billion. Is the world’s pizza too small to go round, or is it big enough and cut unevenly? There are two pizzas to check, food and money, and they do not give the same answer.

Food: big enough, cut unevenly, and some of it dropped

The UN’s Food and Agriculture Organization counts the food available for people to eat in every country, and sets it against what people need. For the world as a whole, over 2023 to 2025, the supply came to 126% of the average need. The pizza is bigger than the plates. FAO says so in plain words in its 2026 hunger report: the world produces enough food for a growing population, and does not get enough healthy food to every person.

Yet about 645 million people, 7.8% of the world, faced hunger in 2025. And some food never reaches a plate. FAO estimates that 13.3% of food is lost between the harvest and the shop, before that supply is counted. The UN Environment Programme puts the food then thrown away at almost a fifth of what reaches shops, restaurants and homes, and that waste is inside the 126%, not on top of it. The two are shares of different amounts, so we do not add them together.

The economist Amartya Sen, who watched the Bengal famine of 1943 as a boy, argued in 1981 that famines have struck in years when the food supply was not much lower than in earlier years without one. People starve when they cannot get food, not only when there is too little of it. That work was part of his Nobel prize in 1998. A few critics have questioned some of his evidence.

Money: cut very unevenly

The World Inequality Report’s figures for 2025: the richest tenth of the world’s adults took 53% of all income, and the poorer half took 8%. Wealth is cut more unevenly still: 75% to the richest tenth, 2% to the poorer half.

So it is cut unevenly. Is it big enough? Cut evenly, the same report’s figures give every adult about $30,100 a year, or about $82 a day. Spread over children too, using the report’s own count of 8.2 billion people and 5.6 billion adults, that is about $56 a person a day. The World Bank’s line for extreme poverty is $3.00 a person a day. The two are not measured the same way: the report counts national income in 2025 prices, and the line is set against household surveys in 2021 prices. But the gap is almost nineteenfold, and no price change since 2021 comes close to closing it. An even cut would put nobody near that line. Per adult, it would also be under a fifth of what the richest tenth have now, and nearly six times what the poorer half have.

That “cut evenly” carries the whole argument of the toy above. It assumes the pizza stays the same size after you cut it differently, and the leak and the hunger cost are exactly the question of whether it would.

And the pizza has grown

In 1990, 43.4% of the world, about 2.3 billion people, lived in extreme poverty on the World Bank’s current line. In 2024, the latest year with enough surveys, it was 10.1%, about 824 million. The Bank says the fall was driven largely by East Asia, China above all, and more recently by South Asia.

The same report’s headline, though, is that the fall has stalled. The Bank estimates about 811 million people in extreme poverty in 2026, a rate essentially unchanged since the pandemic, and expects more in 2030 than today unless growth per person picks up.

So the answer to the question has two halves. For food, there is enough, and it is cut unevenly, with some dropped on the floor. For money, it is cut very unevenly, an even cut would lift everyone far above extreme poverty, and how much growth an even cut would cost is the argument economists have not settled. Both the growing and the slicing matter, and anyone who tells you only one does is selling half a pizza.

If you run a business

You split things every week: hours, the good shifts, a bonus pool, the Friday pizza. The three rules are all available to you, and each needs something different to know. The same for everyone needs nothing. Paying for what each person put in needs a measure of what they put in that the team believes, which the toy simply assumes. Giving by need needs to know what each person needs, and to trust the answer.

A business that cannot see those numbers is left with the same for everyone, or with gut feel. That part, getting a business to where its own records show who did what, is the work we do. If that sounds useful, tell us what you would like to be able to see.

What this does not establish

• The toy is not a model of any economy. Its growth rate, shares and needs are invented round numbers. It shows the shape of the argument, and cannot settle it.
• The toy counts need in slices of a pizza that is always cut in eight, so need grows with the pizza. With needs fixed, a growing pizza would feed Dee in time under any rule, and the hunger cost would fade.
• One knob does two jobs: the slices lost on the way and the slices not chipped in. Okun’s bucket bundles them the same way. In real programmes the two vary separately and depend on how the programme is built.
• The toy leaves out things that matter in life. A share paid to everyone alike carries no stigma, and does not stop when someone earns a little more, as help that depends on need often does. And Okun counted a leak on the receiving side too: someone handed slices may chip in less. The toy leaves that out, which flatters both of the rules that move slices.
• The studies above find associations, across countries or within them. Whether inequality causes slower growth, or both come from something else, is still argued about.
• The world figures come from different sources, years and bases. FAO counts food available to eat, not food eaten. Its loss share is of food produced, and UNEP’s waste share is of food reaching consumers. The World Inequality Report counts adults, and national income before income tax. The poverty line is per person, in 2021 prices, and is measured against household surveys. We kept each figure on its own base and combined none of them, except the one comparison of $56 a person a day with $3 a day, which we flag where it appears.
• The 2025 hunger figure is FAO’s estimate ahead of full data. 2024 is the latest year the World Bank counts poverty from surveys, and its 2026 figure is an estimate.
• Nothing here is a policy recommendation. Where the toy starts, and which costs it counts, are our choices, and the winner changes when they do.

Questions people ask

What is the difference between equity and equality?

Equality gives everyone the same share. Equity gives each person what they need, which can mean different shares, so that everyone has a fair chance. With a pizza, equality is two slices each; equity is more for the person who skipped lunch and less for the one who already ate.

What is an example of equity vs equality?

Four people share an eight-slice pizza. Equality is two slices each, which leaves the hungriest one short and the least hungry with leftovers. Equity cuts the slices to what each person needs, so everyone is full and nothing is wasted, but someone has to know who is hungry.

Is equity or equality better for economic growth?

Nobody has measured that directly: the studies compare more and less unequal economies, not these two ways of sharing. Across countries, IMF and OECD economists found that lower inequality went with faster growth, and IMF economists found that more equal countries had longer growth spells. Studies that followed each country over a few years sometimes found the opposite. Which way it goes depends on how much is lost moving resources around and how much growth is lost when people go without.

What is Okun's leaky bucket?

Arthur Okun's 1975 picture of redistribution: money carried from rich to poor in a leaky bucket, with some lost on the way to administrative costs and to weaker incentives for rich and poor. The question it poses is how big a leak you would accept. Okun's own answer, in his example, was that he would stop at 60 percent.

What is equity theory?

A theory set out by the psychologist J. Stacy Adams in 1963 and 1965: people judge fairness by comparing what they get out against what they put in, and against the same ratio for others. In that sense equity means in proportion to contribution, not according to need.

Is there enough food in the world for everyone?

On the UN Food and Agriculture Organization's measure, yes. Food available for people to eat came to 126% of the world's average need over 2023 to 2025. Yet about 645 million people, 7.8% of the world, faced hunger in 2025. The food exists; it does not reach everyone, and some of it is thrown away.

What does equity mean in business?

Usually ownership: the share of a company that belongs to its owners. It is a different word from the equity in equity vs equality, which is about how something is shared out.

Sources

1. Okun, A. M. (1975). Equality and Efficiency: The Big Tradeoff. Brookings Institution. https://www.brookings.edu/book/equality-and-efficiency/
2. Camacho-Cuena, E., Neugebauer, T. and Seidl, C. (2007). Leaky Buckets versus Compensating Justice. ECINEQ Working Paper 2007-74, which reproduces Okun's leaky bucket passage and his 60 percent answer (the book itself is not free to read online). http://www.ecineq.org/milano/WP/ECINEQ2007-74.pdf
3. The Incidental Economist (2011). Okun's leaky-bucket experiment, 3 March 2011, which reproduces Okun's example of the top 5 percent and the bottom 20 percent. https://theincidentaleconomist.com/wordpress/okuns-leaky-bucket-experiment/
4. Ostry, J. D., Berg, A. and Tsangarides, C. G. (2014). Redistribution, Inequality, and Growth. IMF Staff Discussion Note SDN/14/02. https://www.imf.org/external/pubs/ft/sdn/2014/sdn1402.pdf
5. Berg, A. G. and Ostry, J. D. (2011). Inequality and Unsustainable Growth: Two Sides of the Same Coin? IMF Staff Discussion Note SDN/11/08. https://www.imf.org/external/pubs/ft/sdn/2011/sdn1108.pdf
6. Cingano, F. (2014). Trends in Income Inequality and its Impact on Economic Growth. OECD Social, Employment and Migration Working Papers No. 163. https://doi.org/10.1787/5jxrjncwxv6j-en
7. OECD (2014). Focus on Inequality and Growth, December 2014, page 2: the 3 Gini point, 0.35 point and 8.5 per cent figures. Archived copy; the OECD's own link no longer works. http://web.archive.org/web/20150111105646/http://www.oecd.org/els/soc/Focus-Inequality-and-Growth-2014.pdf
8. Forbes, K. J. (2000). A Reassessment of the Relationship between Inequality and Growth. American Economic Review 90(4), 869 to 887. https://doi.org/10.1257/aer.90.4.869
9. Barro, R. J. (2000). Inequality and Growth in a Panel of Countries. Journal of Economic Growth 5(1), 5 to 32. https://doi.org/10.1023/A:1009850119329
10. Barro, R. J. (1999). Inequality, Growth, and Investment. NBER Working Paper 7038, whose conclusions read the richer-country result as a trade-off. https://www.nber.org/papers/w7038
11. FAO, IFAD, UNICEF, WFP and WHO (2026). The State of Food Security and Nutrition in the World 2026. Hunger in 2025, and the statement that the world produces enough food. https://doi.org/10.4060/cd8306en
12. FAOSTAT. Suite of Food Security Indicators: average dietary energy supply adequacy, World, 2023 to 2025. Data file of 10 July 2026. https://www.fao.org/faostat/en/#data/FS
13. FAO. SDG indicator 12.3.1.a, global food losses: 13.3 percent in 2023. https://www.fao.org/sustainable-development-goals-data-portal/data/indicators/1231-global-food-losses/en
14. UNEP (2024). Food Waste Index, presented to the UN Expert Group on Environment Statistics, October 2024: 19% of food available to consumers wasted in 2022, at retail, food service and households. https://unstats.un.org/unsd/envstats/fdes/EGES11/9UNEP_Food%20Waste%20Index.pdf
15. The Nobel Prize. Press release, The Sveriges Riksbank Prize in Economic Sciences 1998, Amartya Sen, on Poverty and Famines (Oxford: Clarendon Press, 1981). https://www.nobelprize.org/prizes/economic-sciences/1998/press-release/
16. The Nobel Prize. Amartya Sen, Biographical: the Bengal famine of 1943, watched from Santiniketan. https://www.nobelprize.org/prizes/economic-sciences/1998/sen/biographical/
17. World Inequality Lab (2025). World Inequality Report 2026. Income and wealth shares, average income per adult, and the world's adults and people, 2025. https://wir2026.wid.world/
18. World Bank (2026). Poverty, Prosperity, and Planet Report 2026, and the September 2026 global poverty update: extreme poverty at $3.00 a day, 1990 and 2024. https://www.worldbank.org/en/publication/poverty-prosperity-and-planet
19. World Bank (2026). Press release of 26 October 2026: 811 million people in extreme poverty in 2026, a rate essentially unchanged since the pandemic. https://www.worldbank.org/en/news/press-release/2026/10/26/more-and-better-jobs-key-to-putting-poverty-reduction-back-on-track
20. United Nations (2024). World Population Prospects 2024, medium variant, 2026. https://population.un.org/wpp/
21. Adams, J. S. (1963). Towards an Understanding of Inequity. Journal of Abnormal and Social Psychology 67(5), 422 to 436. https://doi.org/10.1037/h0040968
22. Adams, J. S. (1965). Inequity in Social Exchange. Advances in Experimental Social Psychology 2, 267 to 299. https://doi.org/10.1016/S0065-2601(08)60108-2
23. Froehle, C. (2016). The Evolution of an Accidental Meme. Medium, 14 April 2016. https://medium.com/@CRA1G/the-evolution-of-an-accidental-meme-ddc4e139e0e4
24. Interaction Institute for Social Change. Illustrating Equality vs Equity. Artist: Angus Maguire. https://interactioninstitute.org/illustrating-equality-vs-equity/
25. Deutsch, M. (1975). Equity, Equality, and Need: What Determines Which Value Will Be Used as the Basis of Distributive Justice? Journal of Social Issues 31(3), 137 to 149. https://doi.org/10.1111/j.1540-4560.1975.tb01000.x