🌱 Week 7 Homework — Feedback

Student: Alessia Canuto
Assignment: Solow Model with Technological & Population Growth

✅ Overall Assessment

Result: ✅ More than 50% Correct

Strong submission. Both scripts run cleanly, the simulation is correctly parameterised, and the figures look clear with proper labelling. Great job highlighting the economic intuition in the closing comments. The only key omission is the set of steady-state reference lines on the two mandatory plots—adding those horizontal benchmarks will make the comparison across scenarios even clearer.

🔍 Task-by-Task Checklist

#	Requirement	Status	Notes
1	Separate `simulate_growth_tech.m` helper with correct signature	✅	Present with 4 outputs (`k,y,c,A`).
2	Helper preallocates arrays and returns column vectors	✅	Preallocation and final-period assignment handled.
3	Law of motion divides by `(1+n)(1+g)`	✅	Implemented inside loop.
4	Technology path updates with `(1+g)`	✅	Included in helper.
5	Main script sets required parameters (`α, δ, s, T=80, k0, A0`)	✅	Matches homework calibration.
6	Scenario matrix includes `(0,0)`, `(0.01,0.02)`, `(0.02,0.03)`	✅	Implemented as `param_sets`.
7	Reuses simulation outputs for later steps	⚠️	Each plot re-runs the helper instead of reusing stored arrays.
8	Plot `k_t` for the three scenarios	✅	Produces clear line plot.
9	Add steady-state reference lines on `k_t` plot	❌	Missing `yline` overlays.
10	Plot `y_t/A_t` for the three scenarios	✅	Implemented in second figure.
11	Add steady-state reference lines on `y_t/A_t` plot	❌	Same omission as above.
12	Save figures to `Figures/` (PNG/PDF)	✅	Saved as PNG in `Figures/`.
13	Provide steady-state summary (table or print)	✅	Uses loop to print `k*` values.
14	Interpretation answers both homework questions	✅	Concise and accurate economic discussion.
15	Code hygiene (comments, no `cd`, folder guard)	✅	Clean structure and `mkdir` guard.

Score: 12/15 tasks fully correct, 1/15 partial, 2/15 missing → ✅

📈 Evidence & Highlights

```23:60:docs/week7/Homework submissions/AlessiaCanuto_Homework7/week7_homework.m [k, y, c, A] = simulate_growth_tech(alpha, s, delta, n, g, k0, A0, T); % Plot capital per effective worker plot(1:T, k, ‘LineWidth’, 1.5); … plot(1:T, y./A, ‘LineWidth’, 1.5);

```8:24:docs/week7/Homework submissions/AlessiaCanuto_Homework7/simulate_growth_tech.m
    for t = 1:T-1
        y(t) = A(t) * k(t)^alpha;
        c(t) = (1 - s) * y(t);
        k(t+1) = (s*y(t) + (1 - delta)*k(t)) / ((1 + n)*(1 + g));
        A(t+1) = (1 + g) * A(t);
    end

💡 Suggestions for Improvement

Overlay steady-state benchmarks on both plots to visualise target levels. Use something like:
```
k_star = (s / (delta + n + g + n*g))^(1/(1-alpha));
yline(k_star, '--', 'HandleVisibility','off');
```
and similarly for y_star = k_star^alpha on the output plot.
Reuse simulated data by storing it in arrays during the first loop. This avoids re-running the helper function and makes it easier to add steady-state lines or additional diagnostics later.

🧾 Summary

Readable, correct implementation that nails the economic narrative. Adding steady-state reference lines (and optionally storing the paths once) would polish the figures and reduce duplicate work. Overall excellent effort.

Grade: ✅ (More than 50% correct)