The book presents theoretical and empirical research on the integrated assessment of cartels’ effects on national economies. The empirical analysis is based on three cases in Lithuania, a country chosen because it corresponds to the features of a small economy with a developing culture of competition. An integrated assessment of a cartel’s impact by measuring the net economic effect created by its operations on the market is extremely important at the scale of national economies. If a cartel’s true impact is not identified and evaluated, it is impossible to make important strategic decisions, for the whole economy instead of individual affected parties and to establish an optimum baseline for mitigating the harm done to the economy. Thus, an integrated cartel impact assessment can help to more proactively combat cartel agreements on the market and improve the economic welfare of the respective country.