The number of competing daily newspapers in American cities has dwindled until only about 50 cities boast two papers. Of the newspapers in those cities, 23 now maintain separate editorial operations but have joint printing, advertising, and circulation departments. The concept of joint operation is 50 years old, dating from the Depression years when publishers merged parts of their operations in order to survive. This strategy was not legalized, however, until 1970 when industry pressure was successful in persuading Congress to pass the Newspaper Preservation Act (NPA). The industry claimed that the savings that resulted from joint business departments would permit struggling newspapers to stay in business. Congress disliked the alternative--buy outs by the stronger papers and increasing control by chain publishers--and voted for the joint agreements provision, which amounted to an exemption from antitrust laws. Now, the weaker members of the pairs appear to be even more frail and the stronger partners are threatening to terminate the arrangements when present contracts expire. If, over time, joint operation proves to be no more than a burial policy to lay newspapers to rest with dignity, then the NPA is probably safe from attack. If, however, the newspaper industry attempts to be creative and use the antitrust exemption for other purposes, opposition to its continuation can be expected. (RBW)