This article is dedicated to the issue of revealing the cause-effect relationship between public expenses and socially desirable results (effects). Within the frames of this work, the author has provided the analysis of advantages and disadvantages of experimental and pseudo-experimental methods for the quantitative evaluation of effectiveness of the public expenses (search for pair-matching, for difference-differences, discrete design). Besides, the examples of implementation of such methods in the practice of the US and UK public administration at public expenses evaluation have been presented by the authors.