Economy in the Long Run

Session one, and he starts with a warning, not a formula: almost everything you believe about growth — that consumption drives it, that events create it, that government spending buys it — is going to fail an audit in the next hour. The tools are simple (an island, five workers, ten kilos of rice), but every later session stands on what the island proves. Take this one slowly; the course builds.

Course Structure

Course Overview

This macroeconomics course is organized into 15 sessions, each approximately one hour long, held on weekends. The course is structured in two main phases:

Phase 1: Closed Economy Macroeconomics

Phase 2: Open Economy and Trade

Textbooks and References

Primary: Mankiw’s Macroeconomic Principles

Supplementary: Prof will provide readings for each session

Recommended Supplementary Books

The Enlightened Economy by Joel Mokyr - Historical context on economic growth

The New Geography of Jobs by Enrico Moretti - Regional economic development

Real-World Motivations and Examples

He refuses to start with theory. Three puzzles from real places first — each one is a question the course will eventually let you answer, and none of them can be waved away with a headline.

Example 1: Micro-lending in Hyderabad

Street vendors earn 30-40% monthly marginal returns, yet capital does not flow freely to these entrepreneurs. Why doesn’t capital flow to high-return opportunities?

Example 2: Darjeeling vs. Hyderabad - Regional Wage Disparity

Highly-skilled taxi drivers in Darjeeling earn 7,700 rupees/month, while unskilled Hyderabad drivers earn 25,000-40,000 rupees/month. What causes sustained regional growth gaps?

Example 3: Bangalore vs. Hyderabad - FDI and Entry Barriers

Despite superior infrastructure, Hyderabad’s FDI advantage over Bangalore is declining. Hyderabad’s economy is controlled by few families with high entry barriers and rent-seeking.

Historical Growth Context and Modern Exceptionalism

Pre-Industrial Growth Patterns

Modern economic growth is not normal. Economic stagnation was the historical norm.

Pre-Industrial Growth Rate

Annual growth: 0.2% to 0.4%

Duration: 500+ years (1250-1750)

Living standards barely improved across centuries

Modern Growth Episodes

Post-WWII Germany and Japan: Rapid reconstruction

Asian Tigers: Double-digit sustained growth

China: 10% annual growth for 20+ years

Common Misconceptions About Growth

Misconception 1: Consumption Creates Long-Run Growth

Correct: Consumption is a consequence of income, not a driver of growth. Growth comes from increased productive capacity.

Misconception 2: Events Create Growth

Correct: Events shift spending in time but don’t create new productive capacity.

The example that we took of a person choosing to travel to Ahmedabad because of the stadium or a new airport is consumption transfer, not growth.

Misconception 3: Government Spending Creates Growth

Correct: Government transfers redistribute but don’t create productive capacity. Spending may reduce growth through crowding-out.

The Leisure-Work Trade-off: Foundation of Growth

Core Principle

Universal Economic Truth: Growth depends on INCREASED LABOR SUPPLY, not consumption.

Fundamental Framework: Agents trade leisure for work. Growth occurs when the relative value of work increases because new desirable goods/services become available.

Why Would People Work More?

The goods/services available become more desirable

Work becomes more productive

Wages rise relative to leisure preferences

Critical Corollary: Consumption Follows Income

The causal chain: Increased Work Supply → Higher Income → Increased Consumption

The Island Economy Model

Model Setup

Island Economy Setup

Island Economy Parameters

Workforce: 5 workers (A, B, C, D) + 1 supervisor (L)

Production: 10 kg of rice per day

Wage: 2 kg rice per worker

Profit: Supervisor retains 2 kg as profit

GDP: 10 kg rice

Scenario 1: Government Expenditure and Deadweight Loss

Setup and Effects

The government imposes a 2 kg rice tax and hires 1 worker as a police officer.

Initial Changes

Private Workers: 4 (from 5)

Private Output: 8 kg (from 10 kg)

Government Service: 2 kg

GDP (accounting): 8 + 2 = 10 kg (unchanged)

The Problem: Incentive Distortion

Workers reduce labor supply because purchasing power falls through taxation. Output falls further to 7.5 kg private + 2 kg government = 9.5 kg total GDP.

Deadweight Loss

Loss: 0.5 kg (economic waste from the policy)

Government is justified only when services increase productivity enough to offset deadweight loss.

Note what just happened: measured GDP barely moved, but half a kilo of rice simply vanished from the island. That gap between what the accounts say and what people actually eat is the whole point of the scenario — and it’s why “government spending creates growth” fails the audit above.

Scenario 2: Investment and Capital Formation

Setup: Building a Productive Asset

The economy builds a pond that increases future rice productivity. This requires diverting resources from current consumption.

Investment Requirements

2 workers + 50% supervisor time

Current output: Only 5 kg rice

Wage bill: 10 kg

The Financing Problem: Origin of Finance

Workers must be paid 10 kg, but only 5 kg is available. Solution: Workers accept IOUs (bonds). This is the origin of finance - enabling investment through promises of future returns.

The Savings Decision

Workers sacrifice 1 kg current rice for 1 kg of future rice. Investment is viable only if the pond increases future production enough to justify the sacrifice.

Real Interest Rate: The Return to Capital

The real interest rate is the expected percentage return on investment. If the pond increases future rice by 20%, the real interest rate is 20%. Workers demand this rate as compensation for sacrificing current consumption.

Economy in the Long Run

Key Takeaways and Conclusions

Growth Requires Increased Labor or Capital Productivity, Not Spending

GDP = C + I + G is an Accounting Identity, Not Causal

Government Spending Has Deadweight Costs

Investment Requires Savings

Real Interest Rates Reflect Capital Productivity

Modern Growth Is Exceptional

What You Can Now Do

The next time someone tells you a cricket stadium, a wedding season, or a new airport will “boost the economy,” you can ask the island question: did anyone on the island work more, or did rice just move between plates? And when a budget speech promises growth through spending, look for the half kilo that goes missing — the deadweight the accounts never show. Watch one number with new eyes this week: the real interest rate. It is not a policy lever; it is the island’s pond telling you what capital actually earns.

Looking Forward

These foundational principles will guide all subsequent analysis of macroeconomic phenomena. The next sessions will explore how these principles manifest in closed-economy macroeconomics (Phase 1) and eventually open-economy settings with international trade (Phase 2). Continue to Session 2 — The Keynesian Cross, where the clock shortens and prices stop moving.