 The model was developed by Allan Fisher, Colin Clark, and Jean Fourastié.Fourastié saw the process as essentially positive, and in "The Great Hope of the Twentieth Century" he wrote of the increase in quality of life, social security, blossoming of education and culture, higher level of qualifications, humanisation of work, and avoidance of unemployment.The distribution of the workforce among the three sectors progresses through different stages as follows, according to Fourastié