Paper Trail #59: Russell Davidson and Emmanuel Flachaire (2008) "The Wild Bootstrap, Tamed at Last," Journal of Econometrics 146(1):162-169, September 2008. DOI 10.1016/j.jeconom.2008.08.003. VERIFICATION-CAVEAT post: DF 2008 JME paywalled behind ScienceDirect (HTTP 403 to WebFetch) and open-access HAL-SHS mirror also 403'd through Anubis-protected proxy; primary content verified via TWO independent secondary sources both authored by Davidson: MacKinnon 2011 wild-bootstrap survey verbatim quotes DF 2008 simulation summary ('Rademacher outperforms Mammen even when errors are not symmetric') AND Davidson-Monticini 2023 working paper cites DF 2008 extensively on the F1-vs-F2 mechanism. 5th verification-caveat PT (after PT #5 Engle 1982, #6 Bernard-Thomas 1989, #51 Newcombe 1998b, #54 Long-Ervin 2000). Directly grounds today's Stats #59 wild-bootstrap 95% CI on the RBNZ × NZDCAD 11-print sample.
Paper Trail #59— Russell Davidson & Emmanuel Flachaire (2008), The Wild Bootstrap, Tamed at Last, Journal of Econometrics 146(1):162-169, September 2008. DOI 10.1016/j.jeconom.2008.08.003. VERIFICATION-CAVEAT POST: DF 2008 JME paywalled behind Elsevier ScienceDirect (WebFetch HTTP 403); open-access HAL-SHS mirror (hal-00649250) 403’d through Anubis-protected proxy. Primary content verified via TWO independent secondary sources both authored by Davidson himself: MacKinnon 2011 wild-bootstrap survey (KTH-hosted PDF, extracted via pymupdf 1.28.2) verbatim quotes the DF 2008 simulation summary; Davidson-Monticini 2023 working paper cites DF 2008 extensively on the F1-vs-F2 mechanism. 5th verification-caveat PT after PT #5 (Engle 1982), #6 (Bernard-Thomas 1989), #51 (Newcombe 1998b), #54 (Long-Ervin 2000). 45th PT of 59 with FULL primary- source access remains unchanged.

What DF 2008 concluded
Quoting the DF 2008 simulation summary verbatim from MacKinnon 2011’s wild-bootstrap survey (page 18, KTH-hosted PDF, extracted via pymupdf 1.28.2):
Underlying mechanism, verified via Davidson-Monticini 2023 (McGill-hosted, extracted via pymupdf 1.28.2, Section 2): Mammen’s asymmetric F2 introduces a bootstrap-statistic mean bias that only partially offsets the correlation-driven under-rejection; Rademacher’s symmetry eliminates the bias entirely, leaving only the correlation-driven distortion to worry about (which the fast double bootstrap and conditional fast double bootstrap can then correct). Mammen’s 1993 original motivation was to match the third-moment (skewness) of a right-skewed error distribution; DF 2008 show that FOURTH-moment accuracy matters more than THIRD-moment accuracy for the size distortion of the wild bootstrap, and Rademacher (μ₄=1) is closer to the identityE[(v·ê)²] = ê² than Mammen (μ₄=2).
Wild-bootstrap lineage
| Year | Author | Contribution |
|---|---|---|
| 1986 | Wu | proposes wild bootstrap for OLS heteroskedasticity |
| 1988 | Liu | asymptotic theory |
| 1993 | Mammen | F2 asymmetric two-point v ∈ {-(√5-1)/2, +(√5+1)/2} |
| 2007 | Davidson-Monticini-Peel | Economics Letters — reinforces F1 |
| 2008 | Davidson-Flachaire ★ TODAY | F1 vs F2 simulation: Rademacher preferred |
| 2011 | MacKinnon | wild-bootstrap survey; consolidates F1 |
| 2008 | Cameron-Gelbach-Miller | wild cluster bootstrap for clustered SEs |
| 2018 | MacKinnon | wild bootstrap with few clusters |
| 2023 | Davidson-Monticini | bootstrap under heteroskedasticity (same DF-author, WP) |
How this grounds today’s Stats #59
Today’s Stats #59 applies DF 2008’s F1-vs-F2 comparison to the RBNZ × NZDCAD 11-print sample (OLS β̂_u = 277.36 pips per pct-point, t_HC1 = 4.68, t_HC3 = 3.78, HC3 per Long-Ervin PT #54). Bootstrap results on B=20,000 resamples: Rademacher (F1) OLS-residuals 95% CI [174.90, 379.82], Mammen (F2) OLS-residuals CI [168.41, 379.69]. F1 is 2% narrower on the lower bound (matches DF preference). All four wild-bootstrap CIs exclude zero — matches OLS/HC1 rejection. The 2-3% narrowness advantage matches DF’s qualitative finding at a small sample well below DF’s simulation range (their n=50-1000 vs our n=11).
Verification note (verification-caveat)
Primary source (DF 2008 JME) not accessible today: Elsevier ScienceDirect returned HTTP 403 to WebFetch; HAL-SHS open- access mirror hal-00649250 also returned HTTP 403 through the Anubis-protected proxy. Attempted McGill Davidson faculty page — russell-davidson.research.mcgill.ca/articles/ hosts Davidson-Monticini 2023, NOT DF 2008. Two independent secondary sources verified in full via pymupdf 1.28.2 text extraction: (a) MacKinnon 2011 wild-bootstrap survey (34 pages, KTH-hosted PDF) reprints the DF 2008 simulation summary; (b) Davidson-Monticini 2023 “Bootstrap Performance with Heteroskedasticity” (19 pages, McGill- hosted PDF) cites DF 2008 extensively on the F1-vs-F2 mechanism. Both secondary sources are authored by Davidson himself (DF 2008’s first author). Same verification- caveat pattern as PT #5 (Engle 1982) and PT #54 (Long-Ervin 2000). We do NOT quote specific simulation-table cell entries (rejection frequencies at α=1%/5%/10% for various n) — only the qualitative Rademacher-outperforms-Mammen conclusion, which is verbatim in MacKinnon 2011.
Same-day pairing
Paired with Stats #59 (RBNZ × NZDCAD wild-bootstrap CI worked example) and slot 1 RBNZ × NZDCAD (the 11-print sample). Chart via one-off SVG script (F1 vs F2 mass plot with probabilities and moments annotated) reusing scripts/insights-charts/svg + theme primitives with sharp rasterization; scratch script at scripts/insights-charts/.scratch/df2008_dists.ts, not committed.