Temporary increase of official controls at border control posts in the European Union: theoretical assessment of the measures laid down in Commission Implementing Regulation EU/2019/1793.

This study assesses the effectiveness and efficiency of measures provided for by Commission Implementing Regulation (EU) 2019/1793 by determining the rate of consignments not complying with European Union legislation placed on the European market despite increased controls through the use of probability theory and Bayes' theorem methods. In addition, it takes into account different provisions for intensified official controls to improve performance. The study revealed that the effectiveness of measures provided, intended as a reduction in the rate of non-compliant consignments placed on the market, appeared limited despite a great effort in terms of performed official controls. This rate was always lower than the rate of the increased controls and closely linked to the test sensitivity and specificity, determined by the combination of sampling procedures with analytical methods. Furthermore, the efficiency, intended as the ratio between the number of analyses carried out and the number of non-compliant consignments found, was just related to the starting prevalence and sensitivity. Instead, the provision for intensified official controls, based on additional checks carried out following each non-compliant result, was able to significantly reduce the rate of non-compliant consignments placed on the market. In conclusion, this study showed that the protection level offered by the measures laid down might not be proportionate to the effort made. To improve effectiveness and efficiency, sampling procedures and analytical methods with high sensitivity and specificity are needed, aided by the availability of reliable information to identify subsets of consignments with a higher prevalence of non-compliance.