Economics-Resource-Guide

INTRODUCTION

  • Economics studies how societies allocate scarce resources to meet unlimited wants.

  • Two main branches:

    • Microeconomics – decisions of individuals & firms; coordination through markets.

    • Macroeconomics – performance of entire economies; growth, inflation, unemployment.

  • All economic analysis is built on basic assumptions: scarcity, trade-offs, opportunity cost, rationality, gains from trade, use of models, positive vs. normative statements, and pursuit of Pareto efficiency.

SECTION I – FUNDAMENTAL ECONOMIC CONCEPTS

  • Scarcity & Trade-offs

    • Limited resources vs. unlimited wants

    • Every choice involves giving up alternatives (opportunity cost).

  • Opportunity Cost

    • Value of the next-best alternative; not necessarily the monetary price.

  • Rationality

    • People compare marginal benefits with marginal opportunity costs.

  • Gains from Trade

    • Specialization + voluntary exchange ⇒ higher total welfare.

  • Models & Economic Theory

    • Simplified representations (graphs, math) to isolate key relationships.

  • Positive vs. Normative Economics

    • Positive = descriptive / cause-effect; Normative = prescriptive / value-laden.

  • Pareto Efficiency

    • Allocation where no one can be made better off without hurting someone else.

  • Micro vs. Macro

    • Micro = individual markets, price signals; Macro = aggregates, national performance.

SECTION II – MICROECONOMICS

Perfect Competition Model

  • Conditions: many buyers/sellers, standardized product, perfect information.

  • Demand

    • Law of demand (inverse P-Q).

    • Shifters: income, prices of related goods, tastes, expectations, # buyers.

  • Supply

    • Law of supply (positive P-Q).

    • Shifters: input prices, technology, expectations, # sellers.

  • Equilibrium

    • Intersection of demand & supply; automatic adjustment via price.

    • Consumer surplus (area under D above P), producer surplus (area above S below P), total surplus maximized.

  • Elasticity

    • Price elasticity of demand Ed = \frac{\%\,\Delta Qd}{\%\,\Delta P} (absolute value).

    • Influencing factors: substitutes, necessity, market definition, time horizon.

    • Price elasticity of supply Es = \frac{\%\,\Delta Qs}{\%\,\Delta P}.

    • Elasticities determine tax incidence & revenue effects.

  • Government Policy

    • Price ceilings ⇒ shortages, non-price rationing (e.g.
      rent control).

    • Price floors ⇒ surpluses (e.g.
      minimum wage, farm supports).

    • Taxes create price wedge; deadweight loss; burden split according to relative elasticities.

  • International Trade & Comparative Advantage

    • Production-possibility frontier (PPF) shows trade-offs.

    • Comparative—not absolute—advantage drives gains from trade.

    • S = I + NX links saving, investment & trade balance.

  • Theory of the Firm

    • \text{Economic profit}=\text{TR}-\text{Explicit}-\text{Implicit}.

    • MC intersects MR ⇒ profit-maximizing output.

    • Entry & exit drive long-run \pi_e = 0 in perfect competition.

  • Imperfect Competition

    • Monopoly: single seller, barriers (resources, legal, natural).

    • Sets MR=MC; produces less, charges more vs. PC; may price-discriminate.

    • Oligopoly: few sellers; strategic interaction; potential for cartels (e.g.
      OPEC).

    • Monopolistic competition: many firms with differentiated products; zero long-run economic profit but P>MC.

  • Creative Destruction

    • Entrepreneurial profits motivate innovation; new firms/tech destroy old monopolies.

  • Market Failures

    • Externalities: negative (pollution), positive (bees & orchards).

    • Remedies: taxes/subsidies, tradable permits, Coase bargaining.

    • Public goods & common resources:

    • Rivalry / excludability matrix → private, public, common, collective goods.

    • Role of government: provide public goods, define property rights, correct externalities, but beware pork-barrel politics & rent-seeking.

SECTION III – MACROECONOMICS

Long-Run Growth

  • GDP per capita growth driven by:

    • Physical capital accumulation

    • Human capital (education, skills)

    • Technology

    • Natural resources

    • Institutions (legal, political).

  • $$\text{GDP per capita}=\frac{GDP}{POP}=\frac{GDP