Qje Robustness

---
name: qje-robustness
description: Use when building the robustness suite and online appendix for a Quarterly Journal of Economics (QJE) manuscript — the extensive checks QJE referees expect, exploiting the journal's no-page-limit norm. Plans and prioritizes robustness; it does not change the core identification design.
---

# Robustness & Online Appendix (qje-robustness)

## When to trigger

- The main result exists but the robustness section / online appendix is thin
- You want to pre-empt the "what about X?" referee report
- You are unsure which checks are load-bearing vs. padding
- The appendix is a pile of tables with no organizing logic

## QJE expectation: an exhaustive, organized appendix

QJE imposes **no hard page limit** and the modern QJE empirical paper carries a **very extensive online appendix** — the Chetty–Hendren neighborhoods papers (QJE 2018) and Chetty–Hendren–Kline–Saez (QJE 2014) are the genre standard, with online appendices dwarfing the printed text. A short robustness section signals an unfinished paper. But volume is not the goal — *anticipation* is. The appendix should answer, in advance, every serious threat a smart referee would raise, organized so the handling Editor can find each answer fast. Note: at submission everything ships in **one PDF** (no separate appendix file at the initial stage), so the appendix must be cleanly sectioned within that document. Lead with the checks that defend the **identifying assumption**, then **measurement**, then **specification**.

## Robustness priority ladder (defend in this order)

1. **Identification threats first.** The checks that defend exogeneity: pre-trends, placebo timing/outcomes, falsification where the channel is absent, alternative control groups, donor-pool / synthetic checks. These are not optional.
2. **Selection & sample.** Attrition, sample-definition sensitivity, alternative inclusion windows, trimming/winsorizing, outlier robustness.
3. **Measurement.** Alternative outcome/treatment definitions, alternative data sources, measurement-error bounds.
4. **Specification.** Functional form, fixed-effects structure, controls in/out (and a discussion that the estimate is not control-sensitive), clustering alternatives.
5. **Inference.** Wild-cluster bootstrap with few clusters, randomization inference, multiple-hypothesis corrections across outcomes/subgroups.
6. **Magnitude & external validity.** Benchmark the effect size against the literature; show where the result does and does not extend.

## What goes in the body vs. the appendix

| Goes in the main text                                  | Goes in the online appendix (same PDF at submission)     |
|--------------------------------------------------------|----------------------------------------------------------|
| The one or two checks that *make or break* the design  | The full battery of alternative specs                    |
| The headline robustness figure (e.g., event study)     | All variant tables, by category                          |
| A sentence summarizing each appendix result            | Data construction, variable definitions, extra proofs    |

## Checklist

- [ ] Every identification threat has a corresponding check, named and reported
- [ ] Pre-trends / placebo / falsification evidence is in the body, not buried
- [ ] Estimate shown to be insensitive to reasonable specification choices
- [ ] Few-cluster / multiple-hypothesis inference handled
- [ ] Appendix is organized by threat category, not dumped chronologically
- [ ] Appendix is cleanly sectioned within the single submission PDF
- [ ] Each appendix result is referenced and one-line-summarized in the main text
- [ ] Magnitudes benchmarked against prior estimates in the literature

## Anti-patterns

- A two-paragraph robustness section in a paper claiming a causal effect (QJE's no-page-limit norm leaves no excuse)
- Appendix tables with no narrative linking them to specific threats
- Reporting only the checks that pass; hiding the fragile specification
- "Results are robust to a battery of checks (see Appendix)" with no specifics in text
- Padding the appendix with redundant specifications instead of addressing real threats

## Output format

```
【Identification checks】[pre-trends, placebo, falsification, alt controls, ...]
【Selection/sample checks】[...]
【Measurement checks】[...]
【Specification checks】[...]
【Inference checks】[wild-cluster, RI, MHT, ...]
【Body vs. appendix split】what stays in text
【Gaps to close】[...]
【Next step】qje-tables-figures
```