Literary prizes have been awarded for centuries, but in the twentieth century they proliferated and became more global in nature and scope. They are awarded on various levels, from local and national to the international Nobel Prize in Literature; judges are usually prominent writers or professionals in the arts who are asked to choose from a field of prestigious nominees. Groups such as publishers, writers' associations, and foundations like the Pulitzer usually award prizes for works written during that year, whereas the Nobel Prize in Literature is intended to recognize lifetime achievement. Although a literary prize can be an economic boon to the publishers and writers involved, winning a major prize like the Pulitzer or the Nobel is especially significant because it enhances the reputation and career of the individual writer. In the last several decades, however, critics of literary prizes have raised questions about the fairness of selection criteria, the objectivity of the judging process, the judges' openness to and acceptance of diverse styles and minorities, and their susceptibility to literary fashions and cultural trends. Kjell Espmark has argued that the Nobel Prize in Literature has reflected a greater tolerance for new literary styles and movements in the last several decades, and Ralph Gunther has pointed out the multinational and multiethnic character of Nobel winners. On the other hand, William Pratt and Burton Feldman have explored possible reasons for what they consider some notable omissions among Nobel nominees over the years. Pulitzer Prizes have been similarly scrutinized by critics, especially in regard to their criteria and the influence of individual judges on controversial decisions. Thomas P. Adler has written about the treatment of such themes as politics and race relations in Pulitzer-winning plays.