Measuring_The_Cost_of_Living_Lecture_3

Measuring The Cost of Living

Introduction

  • Persistent increases in the overall price level in an economy reduce the purchasing power of money over time.

  • Economists measure price variations with price indices, adjusting economic variables for inflation effects.

  • Understanding measurement is foundational; further discussions will explore inflation's causes and effects.

The Consumer Prices Index and Related Measures

Consumer Prices Index (CPI)

  • Definition: The CPI measures overall prices of goods and services purchased by a typical consumer.

  • Inflation Rate: The percentage change in the price index from one period to another, calculated as:

    • Inflation Rate = (\frac{CPI_{year2} - CPI_{year1}}{CPI_{year1}}) x 100

  • Producer Price Index (PPI): Measures prices of a basket of goods/services bought by firms.

Calculation of the Consumer Prices Index

CPI Calculation Steps

  1. Survey Consumers: Determine a fixed basket of goods.

  2. Price Collection: Gather prices for each good over the years.

  3. Basket Cost Computation: Total the cost of the basket for each year.

  4. Indexing: Choose a base year to compute CPI using:

    • CPI = (\frac{Cost_{current}}{Cost_{base}} \times 100)

  5. Inflation Rate Calculation: Determine yearly inflation from CPI changes.

Example Calculation

  • Basket: 4 hot dogs, 2 burgers.

  • Prices (Years):

    • 2014: €1/hot dog, €2/burger => Total: €8

    • 2015: €2/hot dog, €3/burger => Total: €14

    • 2016: €3/hot dog, €4/burger => Total: €20

  • CPI Computation:

    • CPI 2014 = 100,

    • CPI 2015 = 175,

    • CPI 2016 = 250.

Issues in Measuring the Cost of Living

Factors Adding Complexity

  • Substitution Bias: Consumers may switch products based on price changes (e.g., apples vs. pears).

  • New Goods Introduction: Impact consumer choice and value (e.g., home movie viewing vs. theaters).

  • Quality Changes: Improvements in products alter their value without price reflecting it (e.g., digital cameras).

  • Relevance of CPI: Tools like Personal Inflation Calculators can personalize inflation assessments.

Harmonized Index of Consumer Prices (HICP)

  • Constructed similarly across European countries, allowing for direct inflation comparisons.

  • National indices differ in construction, making cross-country comparisons challenging without HICP.

GDP Deflator vs. Consumer Prices Index

GDP Deflator Characteristics

  • Reflects prices of current goods/services relative to base prices.

  • Monitored alongside CPI for price trend assessment.

  • Divergence due to different good coverage:

    • Examples: Prices of various consumer goods vs. produced goods.

Weighting Differences

  • GDP deflator adjusts with changing production over time.

  • CPI uses a fixed basket, revised periodically.

Adjusting Economic Variables for Inflation

Indexation and Interest Rates

  • Indexation: Automatic adjustment of money amounts for inflation (e.g., wages, tax brackets).

    • Ensures real wages maintain purchasing power.

  • Nominal vs. Real Interest Rates:

    • Nominal Interest Rate: Not adjusted for inflation, represents current earnings.

    • Real Interest Rate: Adjusted for inflation, calculated as:

      • Real Interest = Nominal Interest - Inflation Rate.

Addressing Inflation's Effects

Comparative Real Values

  • Historical salaries adjusted for inflation illustrate relative value changes.

    • Example: MP (\text{(1911)}), £400 vs. (\text{(2012)}), £65,738.

  • Use inflation indices to convert past figures to present values for accurate comparisons.

Summary of Key Points

  • CPI Purpose: Tracks price changes in a consumer basket, indicating inflation rates.

  • Limitations: CPI can overstate living costs due to substitution effects, new product introductions, and quality changes.

  • Comparative Indices: GDP deflator focuses on production; CPI focuses on consumption.

  • Importance of adjusting nominal figures using price indices for accurate financial assessments.