As part of the Philippine government’s efforts to contain the COVID-19 pandemic, the Department of Health has regularly been reporting the number of positive cases, deaths, and recoveries from all over the country. However, there were doubts and allegations of concealment on the reported COVID-19 data. Hence, a test of fraud was conducted by examining the cumulative distribution of the country’s COVID-19 data if this conformed to the principle of Benford’s law. Kolmogorov-Smirnov test (KS) was employed to analyse the difference between the distributions. The results show no significant difference between the COVID-19 data’s first digit distribution and the distribution set by the Benford’s law, thus suggesting no substantial evidence for data manipulation in the reported COVID-19 data of the Philippines.
Keywords: Fraud detection in COVID-19 data, Benford’s law applications[1] WHO Director-General’s Opening Remarks at the Media Briefing on COVID-19. 2020 Mar 11. Retrieved from https://www.who.int/dg/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19---11-march-2020#.
[2] Ducharme, J. World health organization declares COVID-19 a ‘pandemic.’ Here’s what that means. Times; 2020 Mar 11. Available from: https://time.com/5791661/who-coronavirus-pandemic-declaration/.
[3] Department of Health. DOH confirms first 2019-ncov case in the country; assures public of intensified containment measures; 2020 Jan 30. Available from: https://doh.gov.ph/doh-press-release/doh-confirms-first-2019-nCoV-case-in-the-country.
[4] Santos, E. PH reports 276 new COVID-19 cases, total now 8,488. CNN Philippines; 2020 Apr 30. Available from: https://www.cnnphilippines.com/news/2020/4/30/philippines-covid-19-cases-deaths-recoveries.html.
[5] Gotinga, JC. Hospital told not to report coronavirus deaths? DOH probing allegation. Rappler Philippines; 2020 Apr 12. Available from: https://www.rappler.com/nation/doh-probes-hospital-told-not-report-coronavirus-deaths.
[6] Berger, A & Hill, T.P. 2011. Benford’s law strikes back: No simple explanation in sight for mathematical gem. The Mathematical Intelligencer, 33(1): 85–91; 2011.
[7] Diekmann, A. Not the first digit! Using Benford›s Law to detect fraudulent scientific data. Journal of Applied Statistics, 34(3): 321-329; 2007. DOI: https://doi.org/10.1080/02664760601004940.
[8] Goodman, W. The promises and pitfalls of Benford’s law. Significance, 13: 38-41; 2016. https://doi.org/10.1111/j.1740-9713.2016.00919.x.
[9] Kruger, P.S. and Yadavalli, V.S.S.. The power of one: Benford’s law. The South African Journal of Industrial Engineering, 28(2): 1-13; 2017. Available from: DOI http://dx.doi.org/10.7166/28-2-1753.
[10] Collins, J.C. Using excel and Benford’s law to detect fraud. Journal of Accountancy. 2017 April 1, Available from: https://www.journalofaccountancy.com/issues/2017/apr/excel-and-benfords-law-to-detect-fraud.html#:~:text=The%20larger%20the%20better.,for%20this%20type%20of%20analysis.
[11] Moreno-Montoya José. Benford´s Law with small sample sizes: A new exact test useful in health sciences during epidemics. Revista de la Universidad Industrial de Santander. Salud. 52(2): 161-163; 2020. DOI http://dx.doi.org/10.18273/revsal.v52n2-2020010.
[12] Koch, C., & Okamura, K. Benford’s Law and COVID-19 reporting. Economics Letters, 196, 109573; 2020. DOI https://doi.org/10.1016/j.econlet.2020.109573.
[13] Zhang, J. Testing case number of coronavirus disease 2019 in China with Newcomb-Benford law; 2020. Available from: https://arxiv.org/abs/2002.05695.
[14] Balashov, V.S., Yan, Y., & Zhu, X. Are Less Developed Countries More Likely to Manipulate Data During Pandemics? Evidence from Newcomb-Benford Law; 2020. Available from: https://arxiv.org/pdf/2007.14841.pdf.
[15] Department of Health. COVID-19 Tracker Philippines; 2020 April 30. Available from: www.doh.gov.ph/covid19tracker.
[16] Berger, A & Hill, T.P. What is… Benford’s Law? Notices of the AMS, 64(2):132-134; 2017. DOI: http://dx.doi.org/10.1090/noti1477.
[17] Glen, S. “Benford’s Law (The First Digit Law): Simple Definition, Examples” From StatisticsHowTo.com: Elementary Statistics for the rest of us! Available from: https://www.statisticshowto.com/benfords-law/.
[18] InfluentialPoints.com. Kolmogorov-Smirnov Test One & Two-sample, and Related Tests. Available from: https://influentialpoints.com/Training/kolmogorov-smirnov_test-principles-properties-assumptions.htm.