macro

Theories of Consumption

Absolute Income Hypothesis

  • Suggests that individuals base their consumption levels on their current income.

  • As income increases, consumption also increases, but not necessarily in equal proportion.

Relative Income Hypothesis

  • Proposes that an individual’s consumption is determined not only by their own income but also by the income levels of others around them.

  • This implies that relative changes in income affect consumption patterns more than absolute levels.

Permanent Income Hypothesis

  • Introduced by Milton Friedman, this theory suggests that consumption decisions are based on an individual's expectations of lifetime income rather than current income.

  • Changes in expected future income significantly influence current consumption choices.

Life Cycle Income Hypothesis

  • Proposed by Franco Modigliani, this theory states that individuals plan their consumption and savings behavior over their lifetime.

  • People save during their working years and draw on those savings in retirement, leading to a smooth consumption pattern over the life cycle.

Investment Decisions

Autonomous Investment

  • Investments that do not depend on the level of income or output; determined by factors such as expectations and technology.

Induced Investment

  • Investments that vary with the level of income; as income increases, businesses invest more in capital.

Marginal Efficiency of Capital (MEC)

  • The expected return on the last unit of capital stocked.

  • Influences investment decisions as firms compare MEC to the cost of borrowing funds.

Marginal Efficiency of Investment (MEI) Schedule

  • Represents the varying rates of return from investing in additional capital.

  • Shifts in this schedule can indicate changing investment environments.

Theories of Investment

Multiplier Theory

  • Describes how an initial change in spending (investment) leads to a more significant overall increase in income and consumption.

  • The multiplier effect demonstrates the impact on the economy from increased investment.

Accelerator Theory

  • Suggests that investment is related to changes in aggregate demand.

  • The accelerator effect occurs when an increase in demand leads to an even greater increase in investment as firms increase capacity to meet demand.

Interest Rates and Investment

Rate of Interest

  • The cost of borrowing money, which affects investment decisions. Lower interest rates typically encourage more investment.

Role of Finance Beyond the Interest Rate

  • Access to capital and credit, liquidity of financial markets, and investor confidence also significantly impact investment decisions beyond just the interest rate.

Monetary and Fiscal Policies

Instruments of Monetary Policy

  • Central banks use tools such as interest rates, reserve requirements, and open market operations to influence the economy.

  • Monetary policy impacts overall financial conditions, and consequently, investment levels.

Instruments of Fiscal Policy

  • Government spending and taxation policies influence economic activity.

  • Increasing government spending tends to stimulate investment and consumption, while increased taxation may dampen them.

Role and Effects

  • Both monetary and fiscal policies are crucial for managing economic fluctuations and achieving stable growth outcomes.

IS-LM Model

Simple IS-LM Approach

  • The IS (Investment-Savings) curve represents equilibrium in the goods market, while the LM (Liquidity preference-Money supply) curve represents equilibrium in the money market.

  • The intersection of these curves determines the equilibrium interest rate and level of income in an economy.

Elasticity and Shifts of IS and LM Schedules

  • The elasticity of these curves indicates how responsive output and interest rates are to changes in fiscal and monetary policy.

  • Shifts can occur due to changes in external factors, such as consumer confidence, government spending, and investment levels.