Papers & full reports

Published · 23 June 2026

Deconstructing the Friday the 13th Effect: Evidence from Dummy-Variable Regression, Wavelet Analysis, and XGBoost Prediction

Scientific Journal of Intelligent Systems Research, 8(5), 42–56. Authors: Leyi Deng, Xiaowei Feng, Yunya Mao, and Zijia Wan. The published paper states equal contributions and shared first authorship.

English · PDF · 15 pages · 1.3 MB

Published version provided by the journal under CC BY-NC 4.0; authorship, text, and pagination are retained. DOI: 10.54691/rp81mr64.

IMMC 2026 · Original team competition report

Deconstructing the Superstition of Friday the 13th: Evidence from Heterogeneous Regression and Machine Learning Feature Engineering

Problem D, team IMMC26559668. The Chinese competition report and the later English publication are separate versions of the same team project.

Chinese, with an English title · PDF · 21 pages · 16.6 MB

Turning a belief into a question

Our team examined whether Friday the 13th was associated with negative outcomes in the selected data. We separated the particular date combination from other calendar effects and explored how environmental information could enter a prediction model.

Three parts of the analysis

Statistical testing

Dummy-variable regression and comparisons of date effects.

Time-series analysis

Wavelet analysis to examine variation at different time scales.

Prediction

XGBoost models using selected features, alongside a composite well-being index.

Team work and publication

I contributed to model development, analysis, writing, and revisions after the competition. The report received an Honorable Mention in the IMMC Greater China Winter Challenge. The later article lists four authors with equal contributions and shared first authorship.

What the comparison can establish

A non-significant result in selected data does not prove that a date can never matter. The interpretation depends on the observations, variables, and models used. A composite well-being index is also a modeling choice, rather than a direct account of every person’s experience.