Trade protection and tariffs

Trade protection is a set of government interventions that restricts imports or encourages exports in order to alter trade in favour of domestic producers. The government intervenes in what would otherwise be a more open market. The opportunity cost is the benefits of trade that are forgone.

A tariff is an indirect tax that a government imposes on an imported good or service. It pushes up the domestic price of the import and may generate government revenue. Governments can charge a fixed amount per unit or set the tariff as a percentage of the import's value.

Reading the tariff diagram

The standard diagram assumes a small open economy that takes the world market price. Domestic demand slopes downwards and domestic supply slopes upwards, while world supply is horizontal at the world price. At this price, domestic consumption is greater than domestic production. Imports fill the gap.

Once the tariff is imposed, the effective world supply line shifts vertically upwards by the amount of the tax. The domestic price rises. Domestic firms expand production, consumers buy less and imports fall. Label all four domestic quantities: production and consumption before the tariff, followed by production and consumption after it. In each case, the horizontal gap between production and consumption represents imports.

Effects on expenditures, revenues and welfare

Consumer surplus is a monetary measure of the benefit buyers receive when their willingness to pay exceeds the market price. A tariff reduces consumer surplus because the price rises and consumption falls. Both effects must be explained; stating only that consumers pay more is incomplete.

Producer surplus is a monetary measure of the benefit sellers receive when the market price exceeds the minimum price they would accept. Domestic producers gain because they receive a higher price and sell more. If production and employment expand, workers and suppliers linked to the protected industry may benefit too.

The government receives tariff revenue on every unit that is still imported. However, domestic expenditure on imports may rise or fall: the price per imported unit is higher, but fewer units are imported. Foreign producers usually sell fewer units and lose export revenue, though the size of the loss depends on demand conditions.

The lost consumer surplus goes to three places. Part is transferred to domestic producers, part becomes government tariff revenue, and the rest forms two efficiency losses. Welfare loss is a reduction in total economic surplus caused by trades or production decisions that no longer allocate resources efficiently. One triangle shows inefficient extra production by relatively high-cost domestic firms. The other shows mutually beneficial consumption that the higher price prevents.

A tariff can therefore help selected stakeholders while lowering overall welfare. The exact outcome depends on the tariff rate and the price elasticities of domestic demand and supply. It also depends on whether domestic firms can expand, whether the import is an input for other firms, and whether trading partners retaliate. For example, the United States' 2018 tariffs on imported washing machines supported some domestic appliance production, but they also raised retail prices and input costs. The effects reached beyond the protected industry.

Quantities, expenditure and revenue

On a tariff diagram, imports equal domestic consumption minus domestic production:

Here, $M_0$ is imports before the tariff (quantity units per period), $Q_{d0}$ is domestic quantity demanded before the tariff (quantity units per period) and $Q_{s0}$ is domestic quantity supplied before the tariff (quantity units per period).

$P_t$ is the domestic price after the tariff (currency units per good), $P_w$ is the world price (currency units per good) and $t$ is the tariff per imported unit (currency units per good).

After the tariff, $M_1$ is imports (quantity units per period), $Q_{d1}$ is domestic quantity demanded (quantity units per period) and $Q_{s1}$ is domestic quantity supplied (quantity units per period).

Using the prices paid by domestic buyers, import expenditure is:

$IE_0$ is import expenditure before the tariff (currency units per period), while $IE_1$ is import expenditure after the tariff (currency units per period).

Government tariff revenue and foreign export revenue after the tariff are:

$GR$ is government tariff revenue (currency units per period). $FER_1$ is the revenue received by foreign exporters after the tariff, excluding the tax retained by the importing government (currency units per period).

Worked reading from a tariff diagram

Suppose a diagram shows a world price of 10 currency units. Domestic production is 20 units and consumption is 80 units. A tariff of 4 currency units pushes the domestic price up to 14; production rises to 30 and consumption falls to 60.

Imports drop from 60 units to 30 units. Import expenditure moves from 600 to 420 currency units, but foreign exporters receive only 300 currency units after the tariff. The government collects 120 currency units in revenue.

Use the rectangles and triangles to find the changes in surplus:

Here, $\Delta CS$ is the change in consumer surplus (currency units per period).

$\Delta PS$ is the change in producer surplus (currency units per period).

Add the stakeholder changes to calculate the net welfare change:

$\Delta W$ is the change in national economic welfare (currency units per period), so the welfare loss equals 60 currency units. The same result comes directly from adding the production and consumption distortion triangles:

$WL$ is the positive magnitude of welfare loss (currency units per period). Watch the sign convention: a fall in surplus is negative, whereas the stated size of a welfare loss is normally positive.

How a quota works

An import quota is a legal quantitative restriction that limits how many units of a good may enter a country during a stated period. Unlike a tariff, a quota limits the quantity itself rather than placing a tax on each imported unit.

When the permitted quantity is lower than imports under free trade, a shortage develops at the world price. The domestic price then rises until the difference between domestic demand and domestic supply matches the quota exactly. As a result, domestic production rises and domestic consumption falls. Imports drop to the permitted quantity.

Stakeholders, quota rents and welfare

Consumers lose: they pay a higher price and buy less. Domestic producers gain from the higher price and respond by increasing output, which raises their producer surplus. Foreign producers, taken together, sell fewer units.

Multiplying the gap between the higher domestic price and the world price by the quota quantity creates a quota rent, which is income arising from the right to import a restricted good at the lower world price and sell it at the higher domestic price. The recipient of this rent matters:

• If the government auctions import licences, it receives the auction revenue.
• If licences are allocated free to domestic importing firms, those firms may keep the rent.
• If licences are given to foreign exporters, some or all of the rent leaves the importing country through higher foreign export revenue.

Like an equivalent tariff, a quota creates two basic efficiency losses: excessive domestic production and reduced domestic consumption. When quota rents go abroad, national welfare falls further because income transfers to foreign licence holders.

Import expenditure can rise or fall, since consumers pay a higher price but purchase fewer imported units. Foreign export revenue depends on the quota quantity and on whether foreign suppliers capture the quota rent.

Administration shapes the effects too. Freely allocated licences may encourage lobbying and favour established firms. A quota is less transparent than a tariff because its protection is concealed in the restricted quantity and the price that results. For example, Japan's restrictions on rice imports have helped sustain domestic production while keeping domestic rice prices above world-market levels. Consumers bear part of that cost.

Reading and calculating quota effects

For a quota to bind, imports at the quota-determined price must equal the permitted maximum:

Here, $M_q$ is actual imports under the quota (quantity units per period), $Q_{dq}$ is domestic quantity demanded at the quota price (quantity units per period), $Q_{sq}$ is domestic quantity supplied at the quota price (quantity units per period) and $\overline{M}$ is the legal maximum quantity of imports (quantity units per period).

Calculate the rent created by the quota using:

In this formula, $QR$ is total quota rent (currency units per period) and $P_q$ is the domestic price under the quota (currency units per good).

Suppose the free-trade price is 10 currency units. Domestic firms produce 20 units, while consumers buy 80 units. A quota of 30 units pushes the domestic price up to 14; at that price, production rises to 30 and consumption drops to 60.

Imports therefore fall from 60 to 30 units. At the quota price, domestic import expenditure is 420 currency units. Consumer surplus falls by 280 currency units, producer surplus rises by 100 currency units and the quota rent equals 120 currency units.

If the government auctions the licences for their full value, it collects the 120 currency units. The two distortion triangles reduce national welfare by a total of 60 currency units. An equivalent tariff produces the same national welfare result.

The outcome changes if foreign exporters receive the entire quota rent. The importing country cannot count those 120 currency units as domestic income, so its national welfare loss becomes 180 currency units: 60 currency units from production and consumption inefficiency, plus the 120 currency units transferred abroad. Never label the quota-rent rectangle automatically as government revenue. First work out who owns the licences.

Production subsidies for import-competing firms

A subsidy is a government payment or financial concession that lowers a firm's production costs or raises the return from producing a good. When domestic firms compete with imports, a production subsidy shifts the domestic supply curve vertically downwards by the subsidy per unit.

In the small-country model, imports remain available at the world price, so the consumer price doesn’t change. Domestic production rises and imports fall, while domestic consumption stays the same. Consumers see no change in price, consumption or consumer surplus. Domestic producers gain, foreign suppliers lose export sales and the government must fund the subsidy.

Government spending exceeds the gain received by producers. The difference forms a welfare-loss triangle, showing the resources drawn into relatively high-cost domestic production. A production subsidy, unlike a tariff or quota, creates no consumption distortion because the consumer price remains unchanged.

Export subsidies

An export subsidy is a government payment that rewards domestic firms for each unit they sell abroad. Exporters won’t sell in the domestic market for less than the world price plus the subsidy. As a result, the domestic price rises by the subsidy amount.

This higher price encourages domestic production but reduces domestic consumption. Exports expand as the gap between production and consumption grows. Domestic producers gain producer surplus and consumers lose consumer surplus. Meanwhile, the government pays the subsidy on every exported unit, while competing foreign producers may lose market share and revenue.

An export subsidy creates two welfare-loss triangles. One comes from excessive domestic production; the other comes from reduced domestic consumption. Government spending does not represent a welfare loss in full because much of it is transferred to domestic producers. The net loss is the amount left after combining all stakeholder gains and losses.

Its impact depends on how responsive supply and demand are, the payment’s size and duration, and any response from trading partners. Agricultural support under the European Union's Common Agricultural Policy has historically encouraged output and exports in supported sectors. Participating producers benefit, but the policy creates fiscal costs and puts pressure on competing farmers elsewhere. A subsidy can therefore shift income towards one industry without increasing national welfare.

Production-subsidy calculations

With a production subsidy, consumers still pay the world price, but producers receive the world price plus the subsidy payment:

The government pays the subsidy on all subsidized domestic production—not just the increase in output:

Suppose the world price is 10 currency units. Domestic production starts at 20 units, and consumption is 80 units. A production subsidy of 4 currency units raises the producer's effective receipt to 14 and increases production to 30 units. Consumption stays at 80.

Production-subsidy effects at a world price of 10 currency units per good.

Imports drop from 60 units to 50 units, while import expenditure falls from 600 to 500 currency units. Government spending is 120 currency units. Consumer surplus doesn't change. Producer surplus increases by 100 currency units: 80 on the original output and 20 from the triangular gain on the additional output. The welfare loss is therefore 20 currency units.

Export-subsidy calculations

For an export subsidy:

Exports and government spending are calculated as follows:

Suppose an exporting country has a world price of 10 currency units, with domestic production at 80 units and consumption at 20 units. A subsidy of 4 currency units raises the domestic price to 14. Production increases to 100, while consumption falls to 10.

Exports increase from 60 units to 90 units, and government spending is 360 currency units. Consumer surplus falls by 60 currency units, while producer surplus rises by 360 currency units. Therefore:

The welfare loss is 60 currency units. On the diagram, this equals a 20-currency-unit consumption-distortion triangle plus a 40-currency-unit production-distortion triangle. Check the units carefully when quantities are given in thousands or millions: multiplying a price per unit by a quantity in millions produces a result in millions of currency units.

Nature of administrative barriers

An administrative barrier is a non-price trade restriction that uses official procedures, legal requirements or regulatory rules to make importing more difficult or costly. It doesn’t have to involve a tax or an explicit quantity limit. Instead, it may increase compliance costs, cause delays or stop a product from entering the market.

A standard is a prescribed benchmark that a product or production process must satisfy, whereas a regulation is a legally enforceable rule that governs how a product may be produced, tested, labelled, packaged, transported or sold. These measures can take many forms, including technical specifications, product testing and certification. They may also involve customs documentation, inspection procedures, labelling rules, health and safety requirements or environmental requirements.

Effects on markets and stakeholders

Foreign firms that face different national rules may have to redesign their products, carry out extra tests or use separate packaging and documentation. This raises their costs and may reduce the supply of imports. Domestic prices can then rise, total consumption can fall and domestic firms may gain market share. Small foreign firms often face a heavier burden because they spread a fixed certification cost across fewer sales.

For consumers, the result may be higher prices, less variety and weaker competitive pressure. Domestic producers can benefit from protection, although firms that rely on imported components may be hurt by the same procedures. Governments have to pay for inspection and enforcement. Meanwhile, foreign producers may face compliance costs, delays or complete exclusion from the market. If protection persists, domestic firms may also have less incentive to innovate or cut costs, creating further inefficiency.

These effects aren’t always harmful. When standards are scientifically justified, transparent and applied equally to domestic and imported products, they can correct information failures and reduce risks. The challenge is telling legitimate regulation apart from disguised protection. A requirement is more protectionist if it is unnecessarily strict, duplicates equivalent foreign testing, changes without adequate notice or treats imports less favourably than domestic goods.

For example, the European Union's REACH system requires chemical substances sold in its market to be registered and assessed. It can protect health and the environment, but overseas suppliers also face substantial documentation and testing costs. The economic judgement depends on proportionality: whether the rule’s public benefit outweighs the higher costs, reduced competition and possible loss of trade.