Peut-on se fier aux bases de données internationales sur la corruption ? Une confrontation entre enquêtes-experts et enquêtes-ménages en Afrique subsaharienne

The emergence of institutions, governance and especially corruption as major development considerations has generated a whole host of international databases intended to measure these concepts. These databases are now widely used in both the academic world and for public policies, especially for aid allocation. This study looks at the pertinence and limits of global corruption indicators based on experts’ perceptions. The study draws on a wave of original surveys coordinated by the authors and conducted simultaneously in eight African countries. This wave combines two types of surveys on the same subject. The first type of survey covering a sample of over 35,000 people takes an objective measure of the frequency of petty bureaucratic corruption and its characteristics. The second type (mirror survey) reports on 350 experts’ opinions on the matter. A comparison of these two sources paints a clear-cut picture of the experts’ error of assessment. We show that the experts do not provide a good gauge of the real level of corruption. They systematically overestimate the frequency of corruption. Moreover, the ranking of countries derived from their perceptions does not tie in with reality. The experts’ measurement error is all the greater in that the countries are not well graded in the international bases, which penalises the poorest of them. The econometric analyses also find ideological biases, with experts tending to rank countries based on their own political preferences, and the existence of a coherent, but erroneous implicit cultural model of how “Africa works”. The experts tend to massively overestimate the population’s level of tolerance of corrupt practices and underestimate the importance it attaches to matters of “good governance”. These findings make a case for a more cautious and rational use of global governance indicators. Our study also confirms the need to supplement global indicators with surveys of the players concerned.