🌱 Week 7 Homework — Feedback

Student: Sebastiano Bacchi
Assignment: Solow Model with Technological & Population Growth

✅ Overall Assessment

Result: ✅ More than 50% Correct

Excellent submission with correct helper function, proper parameter calibration, and well-organized code. The script efficiently stores results and produces clear plots saved to the correct directory. The bonus convergence speed analysis is thoughtful. The main gaps are: (1) missing steady-state reference lines on both plots, and (2) no printed steady-state summary. The interpretation addresses both homework questions but could be more explicit.

🔍 Task-by-Task Checklist

#	Requirement	Status	Notes
1	Separate `simulate_growth_tech.m` helper with correct signature	✅	Provided with four outputs.
2	Helper preallocates arrays and final values	✅	Column vectors, final period handled.
3	Law of motion divides by `(1+n)(1+g)`	✅	Correct implementation.
4	Technology path updates with `(1+g)`	✅	Included in loop.
5	Main script sets required parameters (`α, δ, s, T=80, k0, A0`)	✅	Matches homework specification.
6	Scenario matrix includes `(0,0)`, `(0.01,0.02)`, `(0.02,0.03)`	✅	Stored in `ng_values`.
7	Reuses simulation outputs for later steps	✅	Stores results in arrays (`k`, `y`, `c`, `A`).
8	Plot `k_t` for the three scenarios	✅	Figure 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	✅	Figure 2 implemented.
11	Add steady-state reference lines on `y_t/A_t` plot	❌	Missing `yline` overlays.
12	Save figures to `Figures/` (PNG/PDF)	✅	Saved to `Figures/` as PNG.
13	Provide steady-state summary (table or print)	❌	No numerical output of `k`/`(y/A)`.
14	Interpretation answers both homework questions	⚠️	Addresses both but could be more explicit about convergence speed mechanism.
15	Code hygiene (comments, no `cd`, folder guard)	⚠️	Uses `addpath` with `userpath` (absolute path concern), otherwise clean.

Score: 10/15 tasks fully correct, 2/15 partial, 3/15 missing → ✅

📈 Evidence & Highlights

14:19:docs/week7/Homework submissions/Homework_7_2264611 Sebastiano Bacchi/Codes/Homework_7_2264611.m for i = 1:n_cases n = ng_values(i, 1); g = ng_values(i, 2); [k(:, i), y(:, i), c(:, i), A(:, i)] = simulate_growth_tech(alpha, s, delta, n, g, k0, A0, T); end

Bonus: Convergence speed analysis (Figure 3) shows good understanding of the dynamics.

💡 Suggestions for Improvement

Add steady-state reference lines: Include yline overlays on both plots showing k* and (y/A)* for each scenario. Calculate these using k_star = (s / (delta + n + g + n*g))^(1/(1-alpha)) and y_star = k_star^alpha.
Print steady-state summary: Add a fprintf block that reports k* and (y/A)* for each scenario. This will provide quantitative backing for your interpretation.
Clarify convergence speed discussion: Your interpretation mentions that “speed of convergence is higher when k is lower” but doesn’t explain the mechanism. Please elaborate on how higher n and g increase effective depreciation and thus convergence speed.
Avoid absolute paths: Replace addpath([userpath, '\Homework_7_2264611\Codes']) with a relative path or ensure the function is in the same directory.

🧾 Summary

Strong submission with excellent code organization and thoughtful bonus analysis. Adding steady-state overlays and a quantitative summary will complete the submission and align with homework expectations.

Grade: ✅ (More than 50% correct)