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Economics. Concepts. Economics studies behaviour and markets What would an individual do if circumstances change? Why do we see what we see? Equilibrium. (super short) Introduction to Economics IES! We have preconceptions
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Economics Concepts
Economics studies behaviour and markets • What would an individual do if circumstances change? • Why do we see what we see? • Equilibrium.
(super short) Introduction to Economics • IES! • We have preconceptions • Economists are just a bunch with common preconceived ideas = Economics paradigm • Unlimited wants • Scarce resources • Choice is a consequence of scarcity • Opportunity cost is a consequence of scarcity • Opportunity cost = too important to miss • Homo economicus = (smart) maximizer
Some (a little) more techy stuff • Decision makers • Individuals • Households • Firms • Individuals/households maximize utility • Scarcity => maximize surplus • Firms maximize profits • Profits = surplus • Why profits? “Corporations are people, my friend!” ® Mitt Romney • Marginal reasoning • Marginal cost • Marginal benefit • Marginal revenue
Policies and morals • Positive statements vs • Normative statements • Policy considerations are a mix of positive and normative
Models and theories • A model is an abstract that can be manipulated easily • A theory = model + observed real-world phenomena • Theories are often a mix of positive and normative • So we say there are ideologies in Economics
The Law of Demand • Maximization • Price is given • Marginal benefit is diminishing • Equilibrium for a person • Price = marginal benefit • Price up => quantity demanded down • Price down => quantity demanded up • The Law of Demand: Price and quantity demanded are inversely related • UNIVERSAL and FOUNDATION
Supply • Maximization • Price is given • Marginal cost is increasing • Equilibrium for a competitive firm • Price = marginal revenue • Price up => quantity demanded up • Price down => quantity demanded down
Competitive market • Information requirements • What price reflects • Marginal value • Marginal cost (= value of something else) • Equilibrium is what we observe (and the supply/demand curves are not)
Comparative statics • Endogenous variables • Equilibrium price • Equilibrium quantity • Endogenous variables • Demand • Price of other goods • Income • Weather • + + + + • Supply • Prices of inputs • Technology • Expectations • Policies that shift the curves
Efficiency • Surplus from trade • Maximized in equilibrium • (what equilibrium?)