Econ drill
A small browser tool for the gap between having read
something and being able to summon it. 143 economics concepts, each
with a definition, an intuition, and an explanation of why the right answer is
right and the wrong one is wrong.
143 concepts
588 questions
12 fields
nothing to install
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What a question looks like
Wrong answers are not drawn at random. They are the concepts you would actually
confuse, so getting one wrong tells you which neighbour you reached for.
what does it claim · micro / externalities
What does the Coase theorem actually claim?
With well-defined property rights and zero transaction costs, private bargaining reaches the efficient allocation regardless of who initially holds the rights; the initial assignment determines only the distribution of surplus.
correct
No bargaining mechanism can be simultaneously efficient, incentive compatible, individually rational and budget balanced when both parties have private values with overlapping supports.
A tax set equal to the marginal external damage at the efficient quantity, which internalises a negative externality by making private marginal cost equal social marginal cost.
what I picked
Overuse of a rival, non-excludable resource because each user bears only a fraction of the congestion cost their use imposes on others.
why that was wrong
That is the Pigouvian tax: A tax set equal to the marginal external damage at the efficient quantity, which internalises a negative externality by making private marginal cost equal social marginal cost.
Coase theorem
DefinitionWith well-defined property rights and zero transaction costs, private bargaining reaches the efficient allocation regardless of who initially holds the rights; the initial assignment determines only the distribution of surplus.
Most relevant in micro,
externalities
IntuitionTwo neighbours arguing over a fence. If talking is free they strike whatever deal makes the land most valuable overall. The law decides who writes the cheque, not where the fence ends up.
…followed by the full explanation, the conditions the result
needs, what it is confusable with, and a link to read further.
What is in it
behavioural (11), econometrics (15), finance (6), game theory (13), growth (9), industrial organisation (11), information (10), labour (10), macro (17), micro (13), trade (12), welfare (16).
70 concepts are pitched at PhD level,
66 at intermediate and 7 at
introductory level. It remembers what you get wrong and shows it to you again
later.
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The explanations were written with the help of an AI and
checked by me. They are here to help you remember, not to be the last word.
Found a mistake? Tell me on GitHub, where the code and
all the content also live.