The causes of food supply inequalities

Food security exists when all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food to meet their dietary needs for an active, healthy life.

It therefore has several dimensions — availability (enough food produced/imported), access (people can afford or obtain it), utilisation (it is nutritious and safe) and stability (this holds over time).

A famine is an extreme, widespread scarcity of food in an area, causing acute malnutrition, mass hunger and a sharp rise in deaths.

It is the most severe point on a scale of food insecurity. Under the internationally used IPC (Integrated Food Security Phase Classification), famine (Phase 5) is only declared when very specific thresholds are crossed — for example at least 20% of households facing an extreme food gap, acute malnutrition above 30%, and deaths exceeding 2 per 10,000 people per day.

It differs from ordinary food insecurity in degree and consequence: chronic food insecurity means people are persistently undernourished, whereas famine is an acute, life-threatening collapse in food access affecting a whole population.

Physical (environmental) causes arise from the natural environment. They include climate (low, unreliable rainfall and drought, e.g. the Sahel), poor or degraded soils and erosion, limited water for irrigation, and pests and disease such as desert locust swarms. These determine how much food a place can physically grow.

Human causes arise from economic, social and political factors. They include poverty (people cannot afford food), unfair trade rules and HIC subsidies that undercut low-income farmers, conflict (e.g. Yemen, South Sudan), poor governance/corruption and weak infrastructure for storage and transport. These determine whether people can access the food that exists and whether it is fairly distributed.

The key distinction is that physical causes limit food availability, whereas human causes mainly control food access and distribution — and modern famines are usually driven more by the human factors.

The evidence shows that food supply inequality is not primarily a problem of global production. The world produces enough food for everyone, so total availability is sufficient — yet over 700 million people are undernourished. This points to a distribution and access problem, not an absolute shortage.

The figure that around one-third of food (about 1.3 billion tonnes a year) is lost or wasted reinforces this. Enormous quantities are discarded in high-income countries (retail and household waste) or lost after harvest in low-income countries (poor storage, transport and refrigeration). Food is therefore available in the wrong places, or spoiled before it reaches people.

Read through Sen's entitlement approach, the coexistence of surplus/waste with hunger confirms that people go hungry because they lack the money or means to command food, not because it does not exist. Inequality is driven by poverty, unequal distribution and weak infrastructure far more than by a global lack of calories.

The implication is that reducing waste and post-harvest loss, and improving access (incomes, safety nets and infrastructure), could cut hunger without needing to grow the total food supply — which is why the causes examined are chiefly economic and political.

Soil degradation and water scarcity are two physical causes that directly cut the amount of food land can produce, and they hit low-income farming populations hardest.

Soil degradation is the loss of soil quality and fertility. It is caused by overgrazing, deforestation, over-cultivation and poor irrigation, which strip vegetation and expose soil to erosion by wind and water. As nutrients and topsoil are lost, yields fall, and in dryland margins such as the Sahel this can lead to desertification, taking land out of production altogether. Because many low-income farmers cannot afford fertiliser or soil-conservation measures, degradation becomes a downward spiral — poor soils give poor harvests, forcing yet more intensive use of the land.

Water scarcity limits food supply because crops and livestock need reliable water. In arid and semi-arid regions, rainfall is low and unreliable, so rain-fed farming is precarious and a failed rainy season means crop failure. Where farmers lack the capital for irrigation, wells or water storage, they cannot buffer against dry years, so supply is both low and highly variable.

The two interact: degraded soils hold less water, and scarce water accelerates degradation, so together they steadily erode the physical basis of food production.

This matters most in low-income countries because a large share of the population depends directly on subsistence, rain-fed farming and lacks the technology (irrigation, fertilisers, drought-resistant seeds) that lets wealthier producers maintain yields — so the same physical constraints translate into far greater food insecurity.

Economic factors are among the most powerful causes of food supply inequality, because they determine both how much food a country can produce and whether its people can access it.

Poverty and lack of access. The most fundamental economic cause is poverty. Following Sen's entitlement approach, hunger usually reflects an inability to command food — the poor cannot afford it even when it is available in the market. This is why hunger persists globally despite enough food being produced, and why over 700 million people remain undernourished.

Unfair trade rules and subsidies. The global trading system is tilted towards high-income countries. HICs pay their farmers large subsidies (e.g. the EU Common Agricultural Policy, US farm support — hundreds of billions of dollars a year), letting them overproduce and dump cheap surpluses on world markets. This pushes prices down and undercuts unsubsidised farmers in low-income countries, whose incomes and production fall. Tariffs on processed goods also trap LICs into exporting volatile raw commodities, giving unstable earnings to import food.

Lack of investment and technology. Low-income farming often lacks irrigation, fertilisers, machinery and improved seeds, so yields stay low and cannot be buffered against bad years. Weak infrastructure (roads, storage, refrigeration) causes heavy post-harvest losses and prevents food reaching markets — supply is lost between field and consumer.

Food price volatility. Because the poor spend a large share of income on food, price spikes (as in 2007–08 and 2010–11, which triggered food riots) rapidly destroy access, tipping vulnerable households into hunger.

Land ownership. Highly unequal land distribution — where a few own large estates and many are landless labourers — concentrates the ability to produce and profit, leaving the majority dependent on volatile wages for their food access.

In conclusion, economic causes operate on both sides of the food equation: they limit production (no investment, unfair trade undercutting farmers) and, above all, restrict access (poverty, price volatility, landlessness). Because they largely control who can obtain food, economic factors are usually the decisive cause of food supply inequality — a point that only strengthens when combined with political causes such as conflict.

Food supply inequality can be traced to both physical factors (climate, soil, water, pests) that limit food availability, and human factors (poverty, trade, conflict, governance) that shape food access and distribution. This essay examines both, and argues that although physical factors set the stage, human factors are usually the decisive cause of who goes hungry — as shown by comparing places at contrasting levels of development.

The case that physical factors matter. The natural environment clearly limits food production. Arid and semi-arid regions such as the Sahel (Niger, Chad, Mali) have low, unreliable rainfall, short growing seasons and recurrent drought, so rain-fed millet and sorghum fail and food supply is low and variable — the 2012 Sahel crisis affected around 18 million people. Soil degradation, erosion and desertification cut yields further, and pests (the 2019–20 East African desert locust upsurge devastated crops) and climate change (shifting growing zones, more extreme droughts and floods) add physical stress. Where the physical base is this fragile, food supply is inevitably constrained.

The stronger case that human factors dominate. However, physical shortfalls only become inequality and famine because of human factors. Following Sen's entitlement approach, famine is usually an access failure: the world produces enough food (about one-third is wasted), yet over 700 million people are hungry because they are poor and cannot command food. Conflict is now the leading driver of acute hunger — in Yemen (civil war since 2015) blockade and destruction created the world's worst food crisis in a country importing most of its food, and in South Sudan civil war produced a declared famine in 2017. Unfair trade and HIC subsidies (EU CAP, US farm support) undercut low-income farmers, while poor governance, corruption and weak infrastructure block aid and prevent food reaching people.

The decisive test — contrasting development levels. The clearest evidence that human factors dominate is that the same physical hazard produces opposite outcomes at different development levels. A severe drought in high-income, well-governed Australia or the USA causes economic loss but no famine, because wealth, technology, insurance, infrastructure and stable governance absorb the shock. The same drought in the low-income, conflict-affected Horn of Africa — as in Somalia in 2011, where drought combined with conflict (al-Shabaab restricting aid) and soaring prices killed an estimated 260,000 people, half of them children under five — becomes catastrophe. The physical trigger is similar; the human context (development, governance, conflict) decides the result.

Conclusion. On balance, the view is largely correct: physical factors are usually the trigger, but human factors — poverty, conflict, trade and governance — determine whether a shortfall becomes inequality or famine. This is why famine has vanished from wealthy, stable countries but persists in poor, conflict-affected ones facing the same physical stresses. However, the two cannot be fully separated — climate change (partly human-driven) is intensifying the physical triggers, so the most accurate view is that human factors are the primary cause of food supply inequality, acting on physical constraints that they increasingly worsen.

Modern famines are rare compared with the past, but where they occur they are increasingly concentrated in war zones. This essay assesses how far conflict is the most important cause of famine, weighing it against physical triggers (drought), economic causes (poverty, prices) and governance failures, and concluding that conflict is usually the decisive cause — but that it works by compounding the others rather than acting alone.

The case that conflict is the most important cause. Almost every recent famine or near-famine has occurred amid armed conflict. Yemen, in civil war since 2015, became the world's worst humanitarian crisis: fighting destroyed farms and livelihoods, blockade and damage to Hodeidah port choked food and fuel imports into a country importing the large majority of its food, and combatants obstructed humanitarian access. South Sudan, in civil war from 2013, saw famine formally declared in parts of Unity State in 2017, driven by fighting that displaced farmers and blocked aid. Conflict is uniquely destructive because it attacks every pillar of food security at once — it cuts production (displacement, destroyed crops), destroys access (wrecked markets, lost incomes, soaring prices), blocks aid, and removes the governance that would otherwise prevent hunger. Starvation can even be used deliberately as a weapon of war. This is why the FAO and WFP identify conflict as the leading driver of acute hunger today.

The case that other factors are equally or more fundamental. However, conflict rarely causes famine by itself. A physical trigger is usually present: Somalia's 2011 famine followed a severe drought, and the Horn of Africa repeatedly faces failed rains. Economic vulnerability is essential too — famine strikes populations already trapped in deep poverty, with no savings and exposed to food-price spikes (as in 2007–08 and 2010–11). Following Sen's entitlement approach, it is the collapse of access/entitlement, not conflict as such, that kills. And governance is pivotal: Somalia 2011 was so deadly partly because the affected region lacked a functioning state and al-Shabaab restricted aid, whereas a comparable drought in stable, wealthy Australia causes no famine at all. This contrast shows that development, governance and economic resilience, not conflict alone, determine the outcome.

Weighing the factors. The most convincing interpretation is that famine is multi-causal: a physical trigger (drought, flood, locusts) meets economic vulnerability (poverty, price volatility) and is tipped into catastrophe by political failure. Conflict is the most important cause because it is the factor that most reliably produces this lethal combination — it manufactures economic collapse, destroys governance and blocks the aid that would otherwise avert famine. Drought without conflict now rarely causes famine (early warning and aid usually prevent it); drought with conflict repeatedly does. In that sense conflict has become the decisive modern ingredient, even though it operates through economic and physical channels.

Conclusion. To a large extent conflict is the most important cause of modern famine — it is present in nearly every recent case (Yemen, South Sudan) and simultaneously destroys availability, access, governance and aid, converting stress into starvation. However, it is not sufficient alone: famine requires a physical or economic shock and deep pre-existing poverty, and its lethality depends on the absence of resilient governance. The most accurate assessment is therefore that conflict is usually the decisive trigger that turns a food crisis into a famine, but that famine remains a multi-causal, and largely preventable, human catastrophe — which is why it now occurs almost exclusively where conflict, poverty and weak governance coincide.

This statement reflects Amartya Sen's entitlement approach, which argues that famine and hunger stem from people's inability to command (access) food rather than from an absolute shortage of it. This essay evaluates the claim, and largely agrees — while noting that in some extreme cases availability genuinely fails.

The strong case for 'access, not availability'. At the global scale, the world produces enough food for everyone, and around one-third of it is lost or wasted (about 1.3 billion tonnes a year), yet over 700 million people are undernourished. Hunger therefore coexists with surplus, which can only be an access and distribution problem. Sen's historical evidence is powerful: the Bengal famine of 1943 (around 3 million deaths) occurred with little fall in food availability — wartime inflation and speculation raised prices while labourers' wages did not, so the poor lost purchasing power (entitlement) and starved amid food they could see but not buy. In the same way, today's hunger is concentrated among the poor, landless and marginalised, showing that poverty and unequal access, not a global lack of calories, drive inequality. Unfair trade and HIC subsidies reinforce this by suppressing poor farmers' incomes and hence their access.

The case that availability still matters. However, the claim is too absolute. In some places availability genuinely collapses. Physical constraints — recurrent drought in the Sahel, soil degradation and desertification, or desert locust swarms (2019–20 East Africa) — really do reduce the food physically present in a region. Most importantly, in blockaded or besieged war zones availability can fail outright: in Yemen, blockade and the crippling of Hodeidah port physically restricted food and fuel imports into a country reliant on them, so food really did become scarce, not merely unaffordable. Here availability and access fail together.

Reconciling the two. The two are best seen as interacting. A physical availability shock (drought, blocked imports) becomes famine only where access is already fragile — where people are poor, prices spike and safety nets are absent. Conversely, even ample availability does not prevent hunger if access is unequal. So availability sets a potential ceiling, but access decides who actually eats. This is why the same drought causes famine in the poor, conflict-hit Horn of Africa (Somalia 2011, ~260,000 deaths) but not in wealthy, well-supplied Australia.

Conclusion. I largely agree with the statement. For the vast majority of food supply inequality — global hunger amid surplus, the Bengal famine, poverty-driven undernourishment — the decisive cause is unequal access, not a lack of availability, exactly as Sen argued. However, the statement is too sweeping: in droughts and, above all, in blockaded conflict zones (Yemen), availability genuinely fails. The most accurate view is that food supply inequality is primarily an access problem, occasionally compounded by real availability failures — so policies must protect entitlements (incomes, safety nets, stable prices, aid access) as much as raise production.