From the modern bibliography there are many significant reports and indications for the action of special interest groups in Greece mainly after the fall of the court in 1974.
Based on the theory of Olson as described in his book “The Rise and Decline of Nations” where developed analytically the implications of the special interest group’s action in a country, focus in the economic factor. With a thorough bibliographic survey, are recorded all the variables that have been used in the research for the impact of the interest groups. After the data for the case of Greece were collected and the normalization was done where it was necessary, the correlation between the variables was first checked. Then the Principal Component Analysis methodology was followed in order to arrive at the fewest variables for the study of the interest groups economic impact. Afterwards, the input and output variables separated, selected a suitable forecasting model of soft computing, the Adaptive Neural Fuzzy Inference System (ANFIS) for the study of the special interest groups impact in the Greek economy. ANFIS is a hybrid model which combines the advantages of Neural Network and the Fuzzy logic. Trying out all the different configurations of the model, as well as the different membership functions the corresponding results were recorded. For each result that emerged, the required evaluation was done, which has as its main criterion the low arithmetical errors of the model. The optimum results emerged from the ANFIS forecasting model, are presented in details along with the rules of the fuzzy logic and the corresponding diagrams, that confirm the success of the prediction.