Relation to the author's previous article, 233. — I. Definitions and assumptions, 233. — II. Price policies of a monopolistic producer selling in both domestic and foreign market, 234. — III. A particular firm engaged exclusively in export trade, 237. — IV. Many exporters and importers in rivalry with one another: monopoly possibilities in the export trade, 238; monopsony possibilities in the import trade, 240; internal monopoly and monopsony, 242. — V. The international interest, 244. — VI. Assumptions, methods, criteria, 247. — VII. Conclusions, 249.