_Advertising and social control._—In contrast with the political machine, which has founded its organized action on the local, personal, and immediate interests represented by the different neighborhoods and localities, the good-government organizations, the bureaus of municipal research, and the like have sought to represent the interests of the city as a whole and have appealed to a sentiment and opinion neither local nor personal. These agencies have sought to secure efficiency and good government by the education of the voter, that is to say, by investigating and publishing the facts regarding the government. In this way publicity has come to be a recognized form of social control, and advertising—“social advertising”—has become a profession with an elaborate technique supported by a body of special knowledge. It is one of the characteristic phenomena of city life and of society founded on secondary relationships that advertising should have come to occupy so important a place in its economy. In recent years every individual and organization which has had to deal with the public, that is to say the public outside the smaller and more intimate communities of the village and small town, has come to have its press agent, who is often less an advertising man than a diplomatic man accredited to the newspapers, and through them to the world at large. Institutions like the Russell Sage Foundation, and to a less extent, the General Education Board have sought to influence public opinion directly through the medium of publicity. The Carnegie Report upon Medical Education, the Pittsburgh Survey, the Russel Sage Foundation Report on Comparative Costs of Public-School Education in the several states, are something more than scientific reports. They are rather a high form of journalism, dealing with existing conditions critically, and seeking through the agency of publicity to bring about radical reforms. The work of the Bureau of Municipal Research in New York has had a similar practical purpose. To these must be added the work accomplished by the child-welfare exhibits, by the social surveys undertaken in different parts of the country, and by similar propaganda in favor of public health. As a source of social control public opinion becomes important in societies founded on secondary relationships, of which great cities are a type. In the city every social group tends to create its own milieu and, as these conditions become fixed, the mores tend to accommodate themselves to the conditions thus created. In secondary groups and in the city fashion tends to take the place of custom, and public opinion, rather than the mores, becomes the dominant force in social control. In any attempt to understand the nature of public opinion and its relation to social control it is important to investigate first of all the agencies and devices which have come into practical use in the effort to control, enlighten, and exploit it.