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ANALYSIS: What Transparency International’s perception index can tell us about corruption in Nigeria

Fighting corruption was a major campaign promise of President Muhammadu Buhari and his All Progressives Congress during Nigeria’s 2015 elections.

As the 2019 polls draw near, with Buhari seeking reelection, corruption remains a crucial topic of public debate.

His government’s corruption fight has come under scrutiny more than once, especially by the main opposition, the Peoples Democratic Party.

The debate shifted in November 2018, when former president Goodluck Jonathan launched a book in which he claimed corruption had worsened under Buhari.

Amid the exchange, Jonathan's media office reportedly said that “under Jonathan and the PDP, Nigeria made her best ever improvement on Transparency International’s Corruption Perception Index, moving eight places forward from 144 to 136 in 2014”.

It continued: “But under President Buhari and the All Progressives Congress, Nigeria has made her worst ever retrogression, moving backwards 12 places from 136 to 148. This is a fact.”

How the index is calculated

The index has two elements: the country ranking and score, Vaclav Prusa told Africa Check. He is a senior advisor at the Civil Society Legislative Advocacy Centre, a Nigerian chapter of Transparency International.

“A country’s score shows the perceived level of corruption in its public sector on a scale of 0 to 100, zero being most corrupt and 100 very clean. The ranking indicates a country’s position relative to other countries on the index.”

Nigeria’s score of 27 out of 100 in 2017 came from nine different sources, he said. These included:

  • Global Insight Country Risk Ratings 2016

  • African Development Bank Country Policy and Institutional Assessment 2016

  • World Justice Project Rule of Law Index Expert Survey 2017/18

  • Economist Intelligence Unit Country Risk Service 2017

  • World Bank Country Policy and Institutional Assessment 2017

  • World Economic Forum Executive Opinion Survey 2017


Transparency International measures the perception of corruption, not corruption itself, Prusa said.

“If perception is correct, it reflects reality, but it is not reality. There is always a gap between perception and reality. And mind you, the corruption perception index only looks at the public sector. It does not cover the private sector.”

Ranking versus score

The score – not the ranking – indicates the perceived level of public sector corruption in a country, Prusa said.

“If Nigeria drops in the ranking, it does not necessarily mean that corruption got worse. It just means there are more countries doing better at that point in time.”

Africa Check looked at Nigeria’s index ranking and scores from 2011, the year Jonathan’s four-year term began, to the most recent one in 2017. The country’s rank varied from 136th to 148th and its score from 24% to 28%. The number of countries surveyed ranged from 168 to 183.


Small shift in score can cause big change in rank

The countries included in each year’s index depends on the country data available in the sources, Michael Hornsby, a communication officer at Transparency International’s head office in Berlin, Germany, told Africa Check.

Hornsby said countries sharing the same score were given equal ranking.

“Several countries often have the same score in the index for a year, meaning they are ranked in the same position. A small change in score can, therefore, lead to a large change in ranking.”

And he warned: “Due to a change in methodology which was implemented in 2012, scores from before and after 2012 cannot meaningfully be compared.” (Note: Before 2012, country scores were calculated out of 10.)

Corruption itself is difficult to quantify

Nigeria’s media often wrongly portray the corruption perception index as a real measure of corruption, Matthew Page of the Carnegie Endowment for International Peace told Africa Check. He published a taxonomy of corruption in Nigeria earlier in 2018.

But measuring actual incidents of corruption is “very difficult to do given the breadth of behaviours that constitute corruption and our ability to quantify their effects”.

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