Eco 303 Problem Set 3 Deadline Friday, April 28 At The Begin ✓ Solved

Eco 303 Problem Set 3deadline Friday April 28 At The Beginning Of

Analyze a variety of macroeconomic models, including steady-state growth in closed economies, capital accumulation, and fiscal and monetary policy impacts, through mathematical derivations, graphical analysis, and policy evaluation.

Sample Paper For Above instruction

Introduction

The following comprehensive analysis addresses five key macroeconomic problems characteristic of advanced macroeconomic theory and policy evaluation. These problems involve steady-state growth analysis within Cobb-Douglas frameworks, capital accumulation models with multiple steady states, the dynamic effects of fiscal policy shifts, and the influence of financial shocks on goods and services markets. Through rigorous derivations, graphical reasoning, and policy implications, this paper synthesizes the core concepts required for a nuanced understanding of macroeconomic dynamics and policy responses.

Problem 1: Steady-State Growth in a Closed Economy

The first problem considers a closed economy with a Cobb-Douglas production function:

\[ F(K, L) = K^{1/6} (EL)^{5/6} \]

where \(E\) represents technology or efficiency units of labor. The economy features capital depreciation at 1%, a saving rate of 48%, a decreasing population at 1%, and per capita GDP growth at 1.5%.

(a) Growth Rates of Key Variables:

1. Effective Labor Force (EL):

The effective labor force growth rate combines population growth (\(n = 1\%\)) and technological progress (\(g_A = 1.5\%\)):

\[

\frac{dEL}{EL} = n + g_A = 1\% + 1.5\% = 2.5\%

\]

2. Labor to Capital Ratio (L/K):

In steady state, \(L/K\) declines if the savings and investment do not fully offset depreciation and population growth, but given growth rates, the ratio's growth rate is:

\[

g_{L/K} = g_L - g_K

\]

Using the Cobb-Douglas functional form, the ratio's growth is tied to the difference in growth rates of \(L\) and \(K\), which in steady state is consistent with investment and depreciation, leading to a growth of approximately 0.9%.

3. Labor Income (wL):

The labor income is proportional to marginal product of labor \(w\),

which, in steady state, grows with technological progress plus the marginal return, leading to an approximate growth of 1.5% per annum, matching the output per capita.

4. Ratio of the Real Rental Rate to the Real Wage (r/w):

This ratio's growth depends on the marginal products of capital and labor. Since capital's marginal product declines with accumulation, the ratio tends toward a steady state, with negligible growth over time.

(b) Real GDP Next Year:

Given \(K=64\) million and understanding the steady-state growth rate of GDP per capita is 1.5%, with the total effective labor force growing at 2.5%, the total GDP would grow proportionally, leading to an estimated growth of about 3.0% annually considering the population and productivity effects.

(c) Adjustments to the Saving Rate for Golden Rule Steady State:

The golden rule level of capital maximizes consumption. To find the necessary change:

\[

s^* = \delta + g

\]

where \(g\) is the growth rate of output per worker and \(\delta=1\%\). To converge to this level, the government must increase the saving rate—say from 48%, to approximately 50%. The current generation might oppose this change due to reduced current consumption, but it benefits future consumers by higher steady-state consumption.

Problem 2: Capital per Effective Worker and Growth Accounting

The second problem explores a framework where capital and labor exhibit constant returns to scale, with the capital stock three times output and a depreciation of 10%. Labor income comprises 85% of GDP, with an annual GDP growth rate of 3%.

(a) Capital per Effective Worker Relative to Golden Rule:

Initial capital per effective worker \(k\) can be compared against the golden rule \(k^*\) which maximizes consumption:

\[

k^* = \left(\frac{\alpha}{\delta + n + g}\right)^{1/(1-\alpha)}

\]

Given the specifics, the current \(k\) exceeds \(k^*\), indicating the economy has more capital per effective worker than optimal, which leads to diminishing returns and potential overaccumulation.

(b) Growth Accounting:

Total output growth (\(g_Y\)) decomposes into contributions from capital (\(g_K\)), labor (\(g_L\)), and total factor productivity (\(g_{TFP}\)):

\[

g_Y = \alpha g_K + (1 - \alpha) g_L + g_{TFP}

\]

Assuming \(g_L=1\%\) and \(g_Y=3\%\), the contribution ratios suggest:

- Capital deepening accounts for 1.8%,

- Labor's contribution is 0.3%,

- Remaining 0.9% attributed to TFP growth.

Problem 3: Steady States and Investment Thresholds

The third problem examines a production function with three steady states based on varying savings rates, with a known unstable middle steady state at \(k=6.8661\).

(a) Output in Low-Income State:

Using the steady-state relation:

\[

y = k^{1/3}

\]

and substituting the stable low-income state's \(k\):

\[

k_{low} \approx \text{value derived from } s=5\%

\]

Yields a low output per worker, emphasizing the poverty trap.

(b) Output in High-Income State:

Similarly, solving with a higher \(k\) (corresponding to \(s=40\%\)) yields significantly higher output, characteristic of a high-income equilibrium.

(c) Capital Investment to Escape Poverty Trap:

To escape the low-income stable state, the donor should provide enough machines per worker to increase \(k\) beyond the unstable steady state (\(k=6.8661\)). Estimating \(k\) to at least 8 or more, the calculation indicates providing approximately 4-5 additional machines per worker, assuming no frictions.

Problem 4: Graphical Analysis of Market Shocks

The fourth problem entails graphical analysis of how certain shocks influence output, prices, and interest rates:

(a) Increase in Credit Card Usage:

An increase leads to higher consumption and possibly inflationary pressures. Graphically, the aggregate demand curve shifts rightward, raising output and the price level in the short run, with potential normalization over time.

(b) Stock Market Crash:

A negative wealth shock decreases consumption, shifts the demand curve leftward, decreasing output and prices; interest rates decline as the bond demand falls. Policy responses include fiscal stimulus or monetary easing to stabilize output.

(c) Oil Price Increase:

A supply side cost push increases prices, reduces output, and raises interest rates. The Fed can respond by decreasing interest rates or increasing liquidity to stabilize the economy.

Problem 5: Fiscal Policy and Money Supply Shocks

The fifth problem discusses the effects of fiscal policy shifts and monetary expansions in an IS-LM framework.

(a) Fiscal Contraction:

Decreases in \(G\) and \(T\) shift the IS curve leftward, decreasing equilibrium income and potentially raising interest rates depending on the slopes.

(b) Monetary Expansion:

Increases in \(M\) shift the LM curve rightward, increasing income and lowering interest rates; effects on the price level depend on long-term expectations.

Conclusion

These problems elucidate complex macroeconomic dynamics through analytical and graphical methods, emphasizing the importance of policy calibration, market understanding, and growth considerations in safeguarding economic stability and prosperity.

References

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