Figure 7

Correlation between RAD and corruption risk. Linear model to correlate the fraction of contracts with RAD ≥ 0.5 per year (as independent variable) with the fraction of contracts by single-bidder per year (i.e. contracts for which PT.AD = 1), as dependent variable, for the EFOS and PCS classes (Left and Right, respectively). To avoid trivial auto-correlations, we exclude from the set corresponding to the independent variable the data of the dependent variables. The years corresponding to the 1st period are marked in green, those corresponding to the 2nd period in purple. Since the number of contracts varies widely from one year to another, the data was weighted by the number of contracts in each class per year to perform the least square fit. For the first model (EFOS class) we obtained an \(R^{2} = 0.72\), an intercept of −0.94, and a slope of 2.01. For the second model (PCS class) we obtained an \(R^{2} = 0.82\), an intercept of −0.41, and a slope of 1.42. All the parameters with \(p_{v}\ll 0.01\)