perm_income#

  • Series: lecture-dp

  • File: lectures/perm_income.md

  • Audit date: 2026-05-28

  • Categories audited: writing, math, code, jax, figures, references, links, admonitions

  • Overall score: 6.3 / 10

  • Priority: MEDIUM

Score breakdown#

Category

Score

One-line note

Writing

6/10

Many Title Case H2/H3/H4 headings.

Math

5/10

Apostrophe transpose for matrices throughout the math.

Code

8/10

Unicode Greek; no pip install needed; PEP8; figsize used 3×.

JAX

out of scope

not a JAX lecture.

Figures

6/10

One ax.set_title(...) with f-string; Title-Case 'Time' xlabel; 3 figsize calls.

References

5/10

Three narrative-author {cite} patterns (e.g. “Hall {cite}…”, “Friedman {cite}…”) — should be {cite:t}.

Links

8/10

Mostly {doc} and clean external URLs; one Wikipedia link to “cointegration” (OK).

Admonitions

N/A

No exercises / proofs.

Issues#

Critical#

None found.

High severity#

  • [qe-writing-006] — Systemic Title Case in H2/H3/H4 headings. Examples: ## The Savings Problem (56), ### Preliminaries (64), ### The Decision Problem (107), ### Assumptions (140), ### First-Order Conditions (186), ### The Optimal Decision Rule (217), #### Responding to the State (274), #### A State-Space Representation (331), #### A Simple Example with IID Income (421), ## Alternative Representations (525), ### Hall's Representation (530), ### Cointegration (599), ### Cross-Sectional Implications (635), ### Impulse Response Functions (683), ### Moving Average Representation (691), ## Two Classic Examples (733), ## Further Reading (945), ## Appendix: The Euler Equation (957). Count: 20+ headings.

Medium severity#

  • [qe-math-002] — Apostrophe transpose ' used in displayed math. Lines: 158 (w_t w_t'), 394 ((x_t - \mu_t)'), 406 (\tilde A', \tilde C'), 417 (\tilde U'), 669 (CC', (I-\beta A'), U'). Count: 6+ blocks.

  • [qe-ref-001] — Narrative-author citations using parenthetical {cite} rather than {cite:t}. Count: 3 occurrences (“Milton Friedman ”, “Robert Hall cast Friedman’s model ”, “Hall suggested…”, “Engle and Granger ”).

  • [qe-fig-003] — One f-string ax.set_title(f'Impulse response: {title} income shock') (line 833).

  • [qe-fig-006] — Title-Case xlabel('Time') on line 501.

Low severity#

  • [qe-writing-001] — Several multi-sentence paragraphs.

  • [qe-fig-001] — figsize= set 3 times.

Strengths#

  • Lecture title in correct Title Case (via {index}).

  • Definitions bolded (“random walk”).

  • \mathbb{E}, \mathbb{E}_t, \mathbb{E}_0 used correctly with braces.

  • Matrices use bmatrix (M4 compliant).

  • “IID” used correctly throughout.

  • Equation labels and {eq} references used cleanly.

  • No \tag, no align-inside-$$, no bold vectors.

  • Unicode Greek; PEP8 code.