IB ECONOMICS Real world examples (rwe's)

IB Economics RWE’s: Reducing Plastic Waste with the UK’s Plastic Bag Tax

For IB Economics students aiming for top marks, the ability to apply theory to real-life policies is crucial. That’s where IB Economics real world examples (RWE’s) come in. One strong case is the UK’s Plastic Bag Tax—a widely implemented policy targeting the overuse of plastic bags, a classic demerit good. It’s an excellent IB Economics RWE for understanding market failure, negative externalities, and how governments can correct overconsumption through pricing mechanisms. Whether you’re crafting an IA or preparing for Paper 1, this policy gives your evaluation real-world impact.

Plastic Bag Tax (United Kingdom): Demerit Goods Policy

The UK’s Plastic Bag Tax is a textbook example of a demerit goods policy. It was introduced to reduce the consumption of single-use plastic bags—a product with significant environmental costs but minimal private expense to consumers in an unregulated market.

Background Information 

The UK’s Plastic Bag Tax was introduced in 2015, requiring large retailers in England to charge 5p (later raised to 10p in 2021) for single-use plastic bags. The aim was to reduce plastic waste, cut down on litter, and shift consumer habits toward reusable alternatives. Prior to the tax, over 7 billion plastic bags were used annually in England alone. The policy followed successful models in Wales and Northern Ireland and was part of broader environmental legislation targeting non-recyclable waste. The revenue raised is donated to charitable causes and environmental groups, adding a public benefit dimension to the intervention.

Economic Theory and Policy Objectives

In IB Economics, a demerit good is one that is overconsumed in the free market due to information failure or negative externalities. Plastic bags impose significant external costs: they pollute rivers and oceans, damage marine ecosystems, and contribute to landfill overflow. These costs are not reflected in the market price, leading to allocative inefficiency. The UK government introduced the tax to internalise these external costs by raising the price of the good, shifting the supply curve leftward and reducing quantity demanded. The tax also aims to nudge consumers towards more sustainable habits, aligning with behavioural economics concepts.

Policy Evaluation 

The tax had an immediate and measurable impact: plastic bag use fell by over 80% within a year of implementation at major retailers. The policy also helped normalise the use of reusable bags. However, some critics argue that the environmental impact may be overstated if consumers switch to heavier plastic alternatives or don’t reuse bags enough to offset their environmental footprint. There were also concerns about inconsistent implementation across smaller retailers. Despite these limitations, the tax is widely viewed as a cost-effective and simple intervention that successfully reduced the use of a common demerit good with minimal public backlash.

Learn with IB Economics RWE’s 

This page is built for IB Economics students and teachers looking to sharpen their analysis with IB Economics real world examples (RWE’s). The UK’s Plastic Bag Tax is a brilliant IB Economics RWE showing how governments regulate demerit goods to address negative externalities and overconsumption. You don’t need to memorise every global policy, but knowing strong examples like this will enhance your IA, strengthen your Paper 1 evaluation, and boost your confidence when applying theory to the real world. Use it. Quote it. Own it.

IB Economics RWE Scorecard: Plastic Bag Tax (UK)

Category	Score (/100)	Symbol Representation
Cost Effectiveness	85
Policy Success	55
Public Support	57
Long-term Viability	88
Macroeconomic Impact	41