Economics · a topic
Public goods and externalities, Taught not just answered.
A real-time, 1:1 lesson on Public goods and externalities: an AI teacher explains it out loud while it visualizes every step. Interrupt it, ask why, and it checks you got it, in 26 languages.
The idea
What is Public goods and externalities?
Public goods and externalities are two reasons markets alone fail to deliver what society wants. A public good, such as street lighting, is non-excludable, so no one can be excluded, and non-rival, so one person's use leaves no less for others; since people can free-ride, firms under-supply it and governments step in. An externality is a cost or benefit falling on someone outside a transaction, like factory pollution or the wider gains from a vaccination, which taxes, subsidies or regulation try to correct.
Where it appears: Class 12 ISC and CBSE Economics, IGCSE and A Level Economics, IB and AP Microeconomics, UPSC prelims and mains.
Where learners get stuck
Why Public goods and externalities is hard
Learners call anything provided by government a public good, confuse non-rival with non-excludable, and cannot show on a graph why a negative externality means too much is produced at the market price.
The picture a good explanation starts with: A two-by-two grid of goods sorted by excludable and rival with examples in each cell, beside a supply and demand graph with a social cost curve above private cost showing the overproduction.
A lesson, step by step
How a lesson on Public goods and externalities goes
01
Ask
Type or say "Why won't private companies provide street lights?" in your own words, in any of 26 languages.
02
Plan
The tutor plans a storyboard, one picture per idea, starting with a two-by-two grid of goods sorted by excludable and rival with examples in each cell, beside a supply and demand graph with a social cost curve above private cost showing the overproduction.
03
Explain
It explains Public goods and externalities out loud while the picture builds step by step, pitched to your level (Class 12 ISC and CBSE Economics and up).
04
Interrupt
Say "wait, why?" or type a doubt: it stops, answers over the picture, and carries on. Ask for a different explanation any time.
05
Check
A checkpoint question makes sure the idea landed, and Tests keep the practice going.
06
Your notes
Upload a PDF or a photo of your class notes or a past paper and the lesson follows your textbook's terms.
Ask it anything
Questions learners ask about Public goods and externalities
- Why won't private companies provide street lights?
- What is the free-rider problem with public goods?
- How does a tax fix pollution from a factory?
Any of these, or your own, typed or spoken. The tutor answers on the picture and adapts to how well you are following.
Questions
Asked, Answered
Can LetMeTeach explain Public goods and externalities?
Yes. Ask in your own words and the tutor plans a lesson on Public goods and externalities: it starts with a two-by-two grid of goods sorted by excludable and rival with examples in each cell, beside a supply and demand graph with a social cost curve above private cost showing the overproduction. Then it explains each step out loud as the picture builds, stops when you say "wait, why?", and ends with a checkpoint question.
Where does Public goods and externalities come up?
Class 12 ISC and CBSE Economics, IGCSE and A Level Economics, IB and AP Microeconomics, UPSC prelims and mains. The lesson is pitched to your level and the exam or curriculum you follow, and you can upload your own notes or past papers so it uses your textbook's terms.
Can I learn Public goods and externalities in my own language?
Yes. LetMeTeach teaches in 26 languages and plans the lesson in the language you choose rather than translating an English one, so the terms match what your textbook says. The Free plan includes 7 hours a month with no card.
Last updated
Learn Public goods and externalities, Starting now.
Ask "Why won't private companies provide street lights?" and watch the answer drawn. The Free plan needs no card.