Colorado Free and Fair
Author: Ole J. Forsberg

Three Elections and Three Tests:
Applying Electoral Forensics to the Rajapaksa Era in Sri Lanka
Ole J. Forsberg, Ph.D.
Oklahoma State University

Overview
Born into a wealthy land-owning family with a popular and politically active father, Mahinda Rajapaksa became the youngest Member of Parliament in 1970. With his strengthening political organization, he became cabinet minister in 1994, leader of the opposition in 2001, Prime Minister in 2004, and President in 2005. As the sixth Sri Lankan president, Rajapaksa commanded the military and oversaw the end of the Civil War with the Liberation Tigers of Tamil Eelam (LTTE).
His three presidential elections, however, were marred by electoral violence and credible claims of electoral fraud. In this poster, I present an analysis of I present the results of a statistical analysis of three Sri Lankan presidential elections: 2005, 2010, and 2015. This analysis focuses on differential invalidation as evidence of a non-democratic setting. Results suggest electoral abnormalities in favor of Mahinda Rajapaksa for all three elections.

Theory
The “Democratic Hypothesis” holds that, among other things, every vote counts the same (has the same probability of counting), regardless of ethnicity, gender, or for whom the ballot was cast. We can model this hypothesis using linear regression to examine the relationship between the invalidation rate and the candidate support rate in each electoral division. Because of heteroskedasticity, the dependent variable needs to be transformed. Here, I use the logit transform.
A statistically significant relationship, is evidence of unfairness in the election, either through ballot box stuffing, differential invalidation, or the like. A negative slope is consistent with differential invalidation (and ballot box stuffing) in favor of the tested candidate. Using the model, one is able to estimate the distribution of possible true vote counts. This allows inference on the election’s actual winner, which may not be the same as the official winner.

The 2005 Election

The 2010 Election

The 2015 Election

Before Election
Mahinda Rajapaksa was Prime Minister
The Liberation Tigers of Tamil Eelam (LTTE) called for Tamils to boycott the election
After Election
Rajapaksa received 50.29% of the valid ballots cast
Wickremasinghe was strongest in his home district and in Tamil areas
Charges of vote fraud were lodged against Rajapaksa
Analysis
Strong evidence of differential invalidation enough to alter the election outcome

Before Election
Rajapaksa was President of Sri Lanka, which made him the civilian head of the Sri Lankan military
Sarath Fonseka was the Commander of the Sri Lankan Army that saw victory over the LTTE war
After Election
Rajapaksa received 57.88% of the valid votes cast
Fonseka was strongest in his home district and in Tamil areas
Charges of vote fraud lodged against Rajapaksa, and Fonseka was imprisoned
Analysis
Strong evidence of differential invalidation enough to alter the election outcome

Before Election
Maithripala Sirisena was the “common candidate” of the opposition
After Election
Rajapaksa lost, having only received 47.58% of the valid votes cast
Sirisena was strongest in his home district and in Tamil areas
Rajapaksa requested the Commander of the Army, the Inspector General of the Police, and the Attorney General for help in staging a coup d'état
Analysis
Strong evidence of differential invalidation

Conclusions
There was strong evidence of differential invalidation helping Rajapaksa in each of the three elections
In the 2005 and 2010 elections, it may have been sufficient to give Rajapaksa the election
In all three elections, differential invalidation also went against the Tamil minority
Because of the high levels of correlation between Rajapaksa support and Tamil population, one cannot distinguish between these two interpretations of the available data

For Further Information
For further information, please contact Ole J. Forsberg at
ole.j.forsberg@okstate.edu
This poster and some supplemental materials can be downloaded from
http://www.electoralforensics.org/reports/JSM2015/
Alternatively, use your cell phone to scan the QR Code at the bottom right

Some Additional Readings
Forsberg, Ole J. “Electoral Forensics: Testing the ‘Free and Fair’ Claim” (PhD diss., Oklahoma State University, 2014).
Huber, Peter J.. “Robust Estimation Of A Location Parameter.” The Annals of Mathematical Statistics 35, no. 1 (1964): 73-101.
Mebane, Walter R., Jr. “Election Forensics: Outlier and Digit Tests in America and Russia.” Address, the American Electoral Process conference, Center for the Study of Democratic Politics, Princeton University, May 1, 2008.
R Development Core Team. “R: A Language and Environment for Statistical Computing.” R Foundation for Statistical Computing. Vienna, Austria, 2010.
Rousseeuw, Peter J., and A. M. Leroy. Robust Regression and Outlier Detection. New York: Wiley, 1987.
Uyangoda, Jayadeva. “Sri Lanka in 2010.” Asian Survey 51, no. 1 (2011): 131-137.

Acknowledgements
Oklahoma State University Department of Statistics
The R-Project at CRAN
The Center for Electoral Forensics