Comprehensive Introduction to Microeconomics, Macroeconomics, and Human Behavior Modeling

Foundations of Economics and Social Sciences

• Social Sciences Definition: Social sciences comprise academic disciplines that study human beings, specifically how people behave, make choices, and interact with one another.

• Academic Disciplines Classification:

  • Anthropology: A social science focused on human societies, cultures, and how humans construct narratives and stories that are maintained over time.

  • Psychology: A social science dedicated to the study of the human mind and individual psychological behavior.

  • Sociology: A social science studying social structures, groups, and categories of people.

  • Political Science: A social science examining political systems, institutions, and their operational dynamics.

  • Criminology: A social science aimed at understanding criminal behavior and law enforcement responses.

  • Natural Sciences: Fields such as biology (study of living organisms/natural phenomena) and chemistry (study of matter and chemical change) study natural phenomena rather than human choices.

• Core Definition of Economics: Economics is the social science that studies how individuals, firms, governments, and societies make decisions when faced with scarcity.

• The Principle of Scarcity:

  • Scarcity is a universal phenomenon that affects every individual regardless of socio-economic status or wealth.

  • Even billionaires with unlimited financial resources remain constrained by time, as there are only $24$\,hours in a day and human lifespans are finite.

  • Key scarce resources include time, household income, available labor supply, and raw physical inputs.

• Trade-offs:

  • Because resources are finite, every choice necessitates a trade-off: engaging in one specific action requires forfeiting the opportunity to engage in an alternative action.

  • Policy analysis operates under the reality that permanent solutions rarely exist; instead, policies only present competing trade-offs with distinct benefits and negative side effects.

Positive versus Normative Economic Statements

• Positive Statements:

  • Definition: Fact-based claims describing how the world actually is or functions.

  • Empirical Verifiability: Positive claims provide observations or predictions that can be confirmed or refuted using empirical data and sensory evidence.

  • Truth Value: A positive statement does not have to be true, but it must be testable.

  • Examples:

    • Checking if today is August 26 or if the time is $08:08$ can be verified instantly against real-world clock and calendar data.

    • "A minimum wage increases unemployment among young and unskilled workers" is a positive statement because labor market data can confirm or refute the hypothesis.

    • Albert Einstein's claim to President Franklin Delano Roosevelt (FDR) that "it is possible to construct a uranium bomb" was a positive statement, which was subsequently confirmed by testing.

• Normative Statements:

  • Definition: Values-based or opinion-based claims assessing the desirability of how the world ought or should be.

  • Non-Verifiability: Normative claims contain value judgments and moral priorities that cannot be objectively confirmed or refuted through data.

  • Linguistic Indicator: Often contain terms such as "should" or "ought."

  • Examples:

    • "The government should increase the minimum wage to help poor people" is normative because it asserts a moral priority without providing a testable mechanism.

    • Albert Einstein's recommendation that the US government should organize and fund nuclear research (which led to Oppenheimer leading the Manhattan Project) was a normative claim based on political and military values. Einstein later expressed deep regret and guilt regarding this recommendation due to the bombings in Japan.

Microeconomics versus Macroeconomics

• Microeconomics:

  • Definition: The branch of economics studying how individual decision-makers behave and interact in specific settings.

  • Consumer Theory: Analyzes individual decision-making from the perspective of single consumers.

  • Producer Theory: Analyzes decisions at the individual firm or producer level.

  • Individual Market Level: Studies the market-level interactions between all buyers and sellers within a specific market for a single good or service.

  • Forest Analogy: Equivalent to examining individual trees in isolation.

• Macroeconomics:

  • Definition: The study of the economy as an aggregate whole, evaluating broad economic phenomena across multiple markets simultaneously.

  • Key Macroeconomic Aggregate Indicators:

    • Gross Domestic Product (GDP): Measures aggregate total income generated within a nation.

    • Unemployment Rate: Evaluates employment conditions across all combined labor markets in an economy.

    • Inflation Rate: Tracks changes in the average price level across all goods and services in an economy over time.

    • Economic Growth Rate: Measures long-term changes in real aggregate GDP at the national level.

  • Forest Analogy: Equivalent to examining the forest in its entirety.

Economic Disagreement and Consensus

• Sources of Disagreement Among Economists:

  • Conflicting Positive Theories: Differences in theoretical frameworks regarding how the economy functions.

  • Differing Values and Priorities: Differences in normative views regarding social goals, ethics, and the proper role of government intervention.

• Case Study on Economic Disagreement: The 2002 Nobel Laureates:

  • Daniel Kahneman:

    • A psychologist by training (educated in Israel) who won the 2002 Nobel Prize in Economic Sciences for integrating psychological insights into economics, establishing the field of behavioral economics (featured in Michael Lewis's book The Undoing Project; Lewis also authored The Big Short and Moneyball).

    • View on the Affordable Care Act (ACA / Obamacare - 2010): Supported the law, asserting it would cap healthcare spending growth while raising the quality and efficiency of healthcare delivery.

  • Vernon Smith:

    • A free-market economist at Chapman University who co-won the 2002 Nobel Prize for establishing experimental economics.

    • View on the Affordable Care Act (ACA / Obamacare - 2010): Opposed the law, asserting it would increase healthcare coverage costs, reduce job creation, and slow broader economic growth.

• Patterns of Agreement Spectrum:

  • Highest Level of Consensus: Positive claims applied to microeconomic topics.

  • Lowest Level of Consensus / Highest Skepticism: Normative claims applied to macroeconomic topics.

Economic Policy Applications and Impacts

• Rent Ceilings:

  • A legally enforced maximum cap on rental housing prices creates persistent shortages because prices cannot rise to balance supply and demand.

  • Landlords have reduced incentives to maintain and repair properties when demand vastly exceeds supply, driving down housing quality and overall quantity available.

  • Economists overwhelmingly agree that rent ceilings diminish both the quantity and quality of available housing.

• Tariffs and Import Quotas:

  • Definition: A tariff is a tax levied directly on imported foreign goods, paid primarily by domestic consumers.

  • Distributional Effects:

    • Domestic Consumers: Harmed by paying higher final market prices.

    • Domestic Producers: Benefit from reduced foreign competition and the ability to charge higher prices.

    • Government: Benefits through the collection of tax revenues.

  • Net Societal Welfare Impact: Tariffs decrease overall social welfare because total economic loss suffered by domestic consumers far outweighs the combined gains received by domestic producers and the government.

• Monetary Policy and Inflation:

  • Inflation is driven primarily by excessive growth in the money supply relative to economic output.

  • The Federal Reserve: Serving as the Central Bank of the United States, the Federal Reserve possesses the sole legal authority to issue money via monetary policy.

Economic Modeling of Human Behavior and Optimization

• The Rationality Assumption:

  • Economists assume individuals are rational actors possessing well-defined goals and explicit objective functions.

  • Rational actors take logical steps to optimize outcomes to achieve their goals as effectively as possible.

  • While individuals may rely on behavioral heuristics for daily low-stakes choices, high-stakes decisions (e.g., purchasing real estate, buying automobiles, managing retirement investments) closely mirror formal economic calculations.

• Components of Optimization:

  • Total Benefits ($TB$): The sum total of all gains, utility, or enjoyment derived from an action or resource consumption.

  • Total Costs ($TC$): The sum total of all direct expenses, indirect sacrifices, monetary outlays, gas, time, and wear and tear incurred from an action.

  • Separability: Benefits and costs are mutually exclusive and distinct parameters without overlap.

• Total Economic Surplus ($TES$):

  • Defined as the quantitative difference between total benefits and total costs:     $\text{Total Economic Surplus} = \text{Total Benefits} - \text{Total Costs}$

  • Objective Function: Rational individual behavior aims directly at maximizing Total Economic Surplus.

• The Marginal Cost-Benefit Principle:

  • A rational decision-maker will choose to undertake an additional unit of an activity if and only if the marginal benefit of that incremental unit exceeds its marginal cost:     \text{Marginal Benefit} > \text{Marginal Cost}

  • Marginal Benefit ($MB$): The change in total benefits resulting from a one-unit increase in an action:     $\text{Marginal Benefit} = \Delta \text{Total Benefits}$

  • Marginal Cost ($MC$): The change in total costs resulting from a one-unit increase in an action:     $\text{Marginal Cost} = \Delta \text{Total Costs}$

Questions & Discussion

• Question: Which of the following academic disciplines is categorized as a social science?

  • Options Discussed: Biology, Chemistry, Anthropology.

  • Correct Answer: Anthropology, because it directly examines human societies, cultures, and historic narratives.

• Question: Evaluate whether the following statements are positive or normative:

  • Statement 1: As of 05/19/2025, Tyler, the Creator had approximately $43,600,000$ monthly listeners on Spotify.

  • Statement 2: Tyler, the Creator will be performing at the Bell Center in Montreal on Tuesday, July 22.

  • Answer: Both statements are positive claims because both present facts that can be verified or refuted using empirical concert and streaming data.

• Question: Which scenario represents a microeconomic observation?

  • Scenario: The average price of gasoline fell from $\$3.25$ to $\$2.79$ per gallon, leading to observable changes in Danny's personal purchasing behavior.

  • Answer: This is a microeconomic observation because it analyzes a single market (gasoline) and an individual decision-maker (Danny).

• Question: How do economists view the following statements?

  • Statement 1: Tariffs and import quotas usually increase the general welfare of society.

  • Statement 2: Inflation is caused primarily by too much growth in the money supply.

  • Answer: Economists generally disagree with Statement 1 (due to consumer welfare losses exceeding producer gains) and agree with Statement 2 (monetary expansion drives price increases).