🌱 Week 7 Homework β€” Feedback

Student: Davide Magnini
Assignment: Solow Model with Technological & Population Growth


βœ… Overall Assessment

Result: βœ… More than 50% Correct

Solid work. Both scripts run without errors, the helper uses the correct law of motion, and the combined subplot neatly presents the transition paths for capital and output per effective worker. To make the submission complete, please add the steady-state reference levels and a short quantitative summary (table or fprintf) before the closing discussion.


πŸ” Task-by-Task Checklist

# Requirement Status Notes
1 Separate simulate_growth_tech.m helper with correct signature βœ… Provided with four outputs.
2 Helper preallocates arrays and final values βœ… Uses row vectors; final-period assignment included.
3 Law of motion divides by (1+n)(1+g) βœ… Fully correct in helper.
4 Technology path updates with (1+g) βœ… Implemented inside loop.
5 Main script sets required parameters (Ξ±, Ξ΄, s, T=80, k0, A0) βœ… Matches calibration in header.
6 Scenario matrix includes (0,0), (0.01,0.02), (0.02,0.03) βœ… Stored in n_g_values.
7 Reuses simulation outputs for later steps ⚠️ Builds an intermediate table, but plots re-run the helper each time.
8 Plot k_t for the three scenarios βœ… Subplot(2,1,1) shows all paths.
9 Add steady-state reference lines on k_t plot ❌ Missing yline overlays.
10 Plot y_t/A_t for the three scenarios βœ… Subplot(2,1,2) covers y_eff.
11 Add steady-state reference lines on y_t/A_t plot ❌ Same omission as above.
12 Save figures to Figures/ (PNG/PDF) βœ… Saved as transition_paths.pdf.
13 Provide steady-state summary (table or print) ❌ No numerical report of k* / (y/A)*.
14 Interpretation answers both homework questions ⚠️ Comments mention dilution and convergence, but could be tighter/more structured.
15 Code hygiene (comments, no cd, folder guard) βœ… Includes mkdir guard and descriptive comments.

Score: 10/15 tasks fully correct, 2/15 partial, 3/15 missing β†’ βœ…


πŸ“ˆ Evidence & Highlights

```39:82:docs/week7/Homework submissions/homework7 Davide Magnini/week7_homework_solution_davide.m for i = 1:3 n = n_g_values(i,1); g = n_g_values(i,2); [k, y, c, A] = simulate_growth_tech(alpha, s, delta, n, g, k0, A0, T); … subplot(2,1,1); plot(1:T, k, β€˜LineWidth’, 1.5); … subplot(2,1,2); plot(1:T, y_eff, β€˜LineWidth’, 1.5);


```31:42:docs/week7/Homework submissions/homework7 Davide Magnini/simulate_growth_tech.m
    for t = 1:T-1
        y(t) = A(t) * k(t)^alpha;
        c(t) = (1 - s) * y(t);
        A(t+1) = (1 + g) * A(t);
        k(t+1) = (s * k(t)^alpha + (1 - delta) * k(t)) / ((1 + n) * (1 + g));
    end

πŸ’‘ Suggestions for Improvement

  1. Add steady-state benchmarks (both k* and (y/A)*) using yline to make each subplot comparable to the solution handout.
  2. Print a steady-state table before the comment block, e.g. fprintf('%4.2f %4.2f %8.4f %8.4f\n', n, g, k_star, y_star); so the discussion references numeric values.
  3. Tighten the written interpretation by explicitly answering: (a) how higher n/g shift steady-state levels per effective worker, and (b) what happens to the speed of convergence.

🧾 Summary

Your code captures the core mechanics and produces clean visuals. With steady-state overlays and a short quantitative summary, the analysis will be fully aligned with the homework expectations.

Grade: βœ… (More than 50% correct)