Jet data analysis

Numerical & Computational Content (jet-data-analysis)

When to trigger

• Your theory paper includes a worked numerical example, a simulation, a computed equilibrium, or (rarely) empirical/experimental evidence
• You want to know how much computational content JET will accept and how to present it
• You need to keep a computation from overshadowing the theorem

The JET rule: theory-first, computation subordinate

JET publishes rigorous, original theoretical results. Empirical, experimental, quantitative, and computational work is welcome only when firmly grounded in theory — i.e., as the illustration or test of a theoretical contribution that is itself the paper's point, never as a stand-alone empirical or computational paper. This skill is deliberately light: most JET papers are pure theory, so the default is minimal numerical content.

How to present numerical content

• Make it serve the theorem. A numerical example should make an assumption bite, exhibit the characterized object, or show tightness of a bound — not stand alone as a finding.
• Keep examples small and transparent. A 2x2 game, a two-type screening problem, or a three-agent matching market usually communicates more than a large simulation.
• Use computation to probe necessity. A computed counterexample is the cleanest way to show an assumption cannot be dropped (feeds jet-identification-strategy and jet-rebuttal).
• Reproducibility. Provide a small self-contained script (SymPy/numpy/scipy, Julia, MATLAB/Octave) that regenerates every reported number and figure; pin versions and set/report seeds for anything stochastic. If the paper uses research data, Elsevier Option C requires a repository citation/link or a cannot-share explanation; if it only has computation, share enough code for the referee to reproduce the numerical claim (see jet-replication-and-data-policy).
• If genuinely empirical/experimental: state the theoretical prediction first, then test it; the prediction is the contribution.

Picking the smallest environment that makes the point

Theoretical claim	Smallest honest illustration	Why it convinces a JET referee
An assumption cannot be dropped	a 2x2 game or two-type screening problem violating only that assumption	the failure is checkable by hand in minutes
A bound is tight	an environment attaining the bound exactly	tightness becomes a verifiable statement, not a plot
A characterized mechanism is implementable	computed transfers/allocations for two or three types	the numbers confirm the closed form line by line
The equilibrium set has the claimed shape	a three-agent matching market or a two-state ambiguity example	the entire set can be enumerated and inspected
A dynamic characterization is operational	one computed path of the recursive contract	the recursion is seen to close

If the smallest environment that exhibits the phenomenon needs more than a page to describe, reconsider whether the example belongs in the body or in an appendix.

Minimal verification script (template)

# verify_example_1.py — regenerates every number in Example 1
# (tightness of the bound in Theorem 2 for the two-type screening problem)
import sympy as sp

v_H, v_L, p = sp.symbols("v_H v_L p", positive=True)
rent = (v_H - v_L) * p                      # information rent at the optimum, matches eq. (7)
bound = sp.Rational(1, 2) * (v_H - v_L)     # the Theorem 2 bound
print(sp.simplify(rent.subs(p, sp.Rational(1, 2)) - bound))  # 0 → bound attained at p = 1/2
# Nothing here is stochastic; if an example is FOUND by random search,
# fix the seed, report it, and ship the search script too.

One short script per numbered Example, named after the theorem it serves, beats one monolithic notebook — referees check examples against statements, not pipelines.

Where computation sits in an accepted JET paper

• As a numbered Example placed immediately after the theorem it illustrates, or as a short "Numerical illustration" subsection — almost never as a stand-alone section competing with the results. Conventions drift across subfields; check recent JET papers in yours.
• Figures generated from computation follow jet-tables-figures: vector output, notation identical to the body, the generating script named in the note.

Anti-patterns

• A large simulation presented as the result, with theory as decoration (off-fit for JET)
• A numerical figure whose underlying values cannot be reproduced
• Calibration/estimation with no theorem behind it (send elsewhere)
• Stochastic illustration with no seed reported

Output format

【Content type】worked example | simulation | computed equilibrium | empirical test | none
【Role】illustrates / tests / counterexample to <theorem/assumption>
【Subordinate to theory?】[Y/N]  ← must be Y for JET
【Reproducible】script + pinned env + seed? [Y/N]
【Next】jet-tables-figures / jet-replication-and-data-policy