When Governments Step In: How Economies Fight Externalities, One Awkward Policy at a Time

How do governments tackle pollution, plastic, and public bad behaviour? A fun, real-world guide to externalities for IB Economics students.

IB ECONOMICS HLIB ECONOMICS MICROECONOMICSIB ECONOMICSIB ECONOMICS SL

Lawrence Robert

3/31/20254 min read

IB Economics Government and Externalities
IB Economics Government and Externalities

When Governments Step In: How Economies Fight Externalities, One Awkward Policy at a Time

Let’s be honest: few things scream excitement like Pigouvian taxation. What if I told you economics has its own Avengers-style team of intervention methods designed to fix the mess markets make? They’re clumsy, sometimes controversial, but they get things done (mostly).

Welcome to the IB Econ edition of “Government vs. Externalities” - a wild ride of taxes, bans, and international handshakes.

Pigouvian Taxes: The Original Intervention Move

Named after the sharply moustached British economist Arthur Pigou (the OG eco-warrior in a waistcoat), these taxes are slapped onto goods that create negative externalities - think cigarettes, petrol, and that suspiciously cheap fast food meal you regretted by 3pm.

Take Singapore’s sugary drink tax, introduced to curb rising diabetes levels. The logic? If you’re going to guzzle Coke like it's water, you should at least pay for the future hospital bill you might need. Pigouvian taxes aim to reflect the true cost of our choices - not just to us, but to society.

But here's the catch: if you're addicted (or if demand is inelastic), like with smoking, higher prices don’t always mean lower consumption. So, while the tax might raise funds, it may not fix the problem. Still, governments love it - extra revenue and virtue signalling? Yes, please.

Carbon Taxes: Polluters Pay Up

Climate change is the ultimate externality. Enter carbon taxes. These are Pigouvian taxes for big polluters: coal, oil, diesel - all the carbon-intensive stuff.

Sweden introduced a carbon tax back in the 1990s, the Swedish carbon tax and guess what? Their emissions fell while their economy grew. Boom. It worked. Sort of.

But here’s the trick: rich households and firms just pass on the cost or absorb it. Poorer folks? They feel the squeeze more. That's what economists call regressive taxation. (Fun fact: in France, carbon tax protests got so intense they sparked the Yellow Vest movement.)

Legislation & Regulation: Thou Shalt Not Smoke in the Playground

Sometimes governments say “enough with the market forces” and just lay down the law.

Example? Minimum legal age laws - like the UK's ban on under-18s buying cigarettes or gambling. Or plastic bag bans, which popped up everywhere from Kenya to the UK. (Kenya's is famously strict-fines and even jail time if you’re caught selling them. No joke.)

But strict laws can backfire. The black market for plastic bags? It's a thing. Economics loves a loophole.

Education & Awareness: Because Taxes Aren’t Always Enough

Not everything needs a tax or a ban. Sometimes, you just need people to get it.

Australia’s anti-smoking campaigns - those brutal images on cigarette packs - are a classic example. Effective? Yes, but slowly. Behaviour change takes time, and not everyone listens (looking at you, conspiracy YouTube brothers).

Also, public campaigns cost money, and there’s always the question of whether that money might be better spent elsewhere (hello, opportunity cost).

Tradable Permits: Pollution Trading Cards

Tradable permits sound boring until you realise they’re basically Pokémon cards for pollution rights. A country sets a pollution cap, then gives or sells permits to firms. If you pollute less, you can sell your unused permits to others. Profit meets the planet.

The EU Emissions Trading Scheme is one of the biggest in the world, and it's working... ish. Critics argue it favours big firms and lets rich countries outsource pollution to poorer ones.

Still, it’s one of the few methods that harnesses market power for good. And anyway...who doesn’t love a good cap-and-trade debate?

International Agreements: Teamwork (Sometimes)

Here’s the thing about externalities: they often don’t respect borders. That’s why we get climate summits, treaties, and serious photo ops at places like the COP conferences.

These work best when countries actually follow through. (Looking at you, everyone who signed and ignored Kyoto Protocol.) But when they do work - like the Montreal Protocol on ozone-depleting substances - they make a massive impact.

Collective Self-Governance: Ostrom's Wisdom

Finally, let’s talk about Elinor Ostrom - Nobel Prize winner and all-round legend. She showed that local communities often manage shared resources better than governments. Why? Skin in the game, basically.

Think of community-managed forests in Nepal or local fishing quotas in Iceland. When people care and cooperate, overfishing and overuse drop. Amazing, right? And zero taxes needed.

Subsidies & Direct Provision: The Feel-Good Moves (With Costs)

Want more people on buses? Subsidise public transport. Need healthier school meals? Subsidise veg. Governments use subsidies to nudge people towards merit goods.

But these schemes aren’t free. Taxes fund them, and poorly designed subsidies lead to inefficiency and - yep - welfare loss. Not to mention admin costs that can bloat faster than a free school lunch queue.

When things get really serious, governments just provide the goods themselves - education, healthcare, public parks. Everyone benefits. But again: costs, inefficiencies, and political drama often follow.

Final Thought: Government Intervention = Necessary Mess

Let’s face it: governments rarely get it perfect. But when markets fail, someone’s got to step in. Whether it’s taxing polluters, subsidising trains, or banning dodgy drinks, each intervention brings trade-offs, delays, and complaints.

Still, when done right (and that’s a big if), these policies protect people, the planet, and future generations.

So next time you're annoyed by a 5p plastic bag charge, remember - it’s not just a tax. It’s a tiny, slightly annoying attempt to fix a much bigger mess.