Lecture_6
Principles of Macroeconomics
Instructor: Alvaro Boitier
Institution: Babson College
Semester: Fall 2024
Basic Tools of Finance
Reference: Chapter 14 - Mankiw's Principles of Macroeconomics (10th edition)
Introduction
Key topics for discussion:
Comparing sums of money over time
Managing risk
Valuing an asset using time and risk analysis
Understanding economic bubbles
Present Value vs Future Value
Understanding Value Over Time:
Scenario 1: Choosing between receiving $100 today versus $100 in 10 years.
Scenario 2: Choosing between receiving $100 today versus $300 in 10 years.
Essential Definitions
Future Value: The amount of money a current sum will yield in the future given interest rates.
Present Value: The current worth of a future sum of money given a specified rate of return.
Compounding: The process where interest is earned not only on the principal but also on previously earned interest.
Compound Interest
Formula for Future Value:
[\text{Future Value} = Pv \times \left(1 + \frac{r}{100}\right)^{N}]
Yearly Accumulation: Each year, money grows by a factor based on the interest rate.
Example Calculations:
For 1 year: (100 + 100 \times \frac{r}{100} = 100 \times (1 + \frac{r}{100}))
For N years: (100 \times (1 + \frac{r}{100})^{N})
Discounting
Determining how much needs to be invested today to achieve a future value at a given interest rate:
Formula: (Pv = Fv \times \left(1 + \frac{r}{100}\right)^{-N})
Discount factor: (\frac{1}{(1 + \frac{r}{100})^{N}})
Examples of Future Value Calculation
Investing $1000 at 0.04% APR for 5 years.
Retirement savings goal: How much to save today to achieve $1 million in 30 years at a 9% return.
Compounding Monthly Rates
Monthly rates reported by BLS or BEA (e.g., inflation, GDP growth).
Yearly inflation calculated from monthly: (\left(1 + \frac{\text{monthly rate}}{100}\right)^{12} - 1)
Example: 1% monthly inflation leads to a yearly inflation of approximately 12.68%.
Average Growth Rate
To find average yearly GDP growth over time lapse:
Identifying cumulative growth and using geometric mean formula for calculation.
The Rule of 70
Formula: Time to double an investment = (\frac{70}{x}) where x is growth rate.
Risk and Its Management
What is Risk?
The uncertainty regarding investment returns.
Risk Preferences:
Risk Averse: Prefers certainty.
Risk Seeking: Prefers uncertainty.
Risk Neutral: Indifferent towards risk.
Insurance as Risk Management
Insurance spreads risk rather than eliminates it.
Pricing based on probability of risk and expected losses.
Diversification
Key strategy to reduce investment risk by allocating capital across various assets.
Impact of standard deviation as a measure of portfolio risk.
Diversification can eliminate firm-specific risks but not market-wide risks.
Risk-Return Trade-Off
Higher potential returns correlate with higher risks.
Example with portfolios of stocks and bonds demonstrating their risk-return profiles.
Efficient Market Hypothesis (EMH)
Asset prices reflect all publicly available information.
Stock prices adjust based on new information, making them unpredictable based on past data.
Limitations of EMH
Past performance not guaranteed for future results.
Market anomalies and behavioral factors lead to investor irrationality.
Bubbles and Their Signs
Definition: Occurrence when asset prices dramatically rise above intrinsic values followed by a significant drop.
Indicators of a bubble:
Rapid price increase without justification.
Media hype and stories of wealth.
Investor enthusiasm mixed with envy and FOMO (fear of missing out).
Historical Examples of Bubbles
Tulip Mania: Early 17th-century economic bubble involving tulips in the Netherlands.
Dot-com Bubble: 1996-2000 tech market boom followed by a crash.
Housing Bubble: 2002-2006 U.S. housing market bubble results in the 2008 crisis.
Cryptocurrency Bubbles: Repeated cycles of value surges and collapses in Bitcoin, Ethereum, etc.
Future of Bitcoin?
Discussion raises questions on sustainability and future valuations.
Questions & Comments
Open floor for discussion regarding principles of macroeconomics and definitions thereof.