摘要:AbstractThis paper presents a case study from Porto-based public transport operatorSociedade de Transportes Colectivos do Porto(STCP) to closer investigate the relation between managerial decisions and economic indicators in public transport, such as efficiency and effectiveness. By means of Data Envelopment Analysis (DEA) the company’ performance results between 1946 and 2004 are analyzed. The second part of the analysis serves to explore the managerial history of STCP and to point out main decisions, policies or other decisive factors in the framework of the company's performance. Our approach aims at identifying the magnitude of these decisions within the operational framework and their time-lags. The analysis has shown that certain managerial decisions directly influence the operational activity in the following years and considerably affect the overall performance of the services provided. The decisions are mostly linked to an increase of social benefits and privileges, political and social environment, the implementation of the single agent policy and operational leasing. Another essential conclusion is the identification of a certain time-frame of such influence. Results show the existence of time-lags between decisions and performance, usually representing medium term periods from 2 to 4 years. The results might be translated into policy recommendations, e.g. for setting up the regulatory framework that achieves a systems best performance.