International trade in the synthetic resins has been small. Germany has been the principal exporting country. There are a number of reasons for the negligible movement of these materials in international trade, the chief of which are active home markets in the principal producing countries; the existence of patents of a basic nature which limited trade to the owners and licencees under them; affiliation of producing companies in different countries with allocation of the world market; and high tariff barriers in many countries. The principal domestic producer of tar-acid resins is affiliated with firms in Germany, the United Kingdom, France, Italy, Canada, and Japan. The two principal American makers of urea resins have or have had agreements as to patents, exchange of technical information, and probably markets, with producers in Great Britain. Similar conditions exist with other types of resins. In 1937 production of all synthetic resins in the United States amounted to 162 million pounds and imports to less than 674,000 pounds (see table 13, p. 58). Production of tar-acid resins in that year amounted to 79.8 million pounds; alkyd resins to 61.2 million pounds and all coal-tar resins to 141 million pounds. Imports of all coal-tar synthetic resins (which would include both tar acid and alkyd as well as others) amounted to only 19,000 pounds. Coal-tar resins are dutiable at 7 cents per pound and 45 percent ad valorem based on American selling price. On the small imports in 1937 the duty collected averaged 54 percent ad valorem on American selling price and would have averaged much higher had it been calculated upon foreign value as are most duties. In 1937 the production of non-coal-tar resins totaled about 21 million pounds. In that year imports of non-coal-tar resins totaled 65,000 pounds. Imports of non-coal-tar resins, other than vinyl resins, amounted to less than 2,000 pounds. These were dutiable at 4 cents per pound and 30 percent ad valorem on foreign value, equivalent on the average to 48 percent ad valorem. The vinyl resins have been imported into the United States in increasing quantities in recent years. The principal foreign producer, in Canada, developed markets in the United States, but is a joint owner of a plant now under construction in this country. Imports of vinyl resins in 1937 were 653,000 pounds. These were dutiable at 3 cents per pound and 15 percent ad valorem on foreign value, equivalent to 25 percent ad valorem. It is apparent that foreign competition with United States producers in the home market has been and is likely to continue insignificant under existing duties. With a large home market and generally favorable conditions with respect to the necessary raw materials and the technical skills, this situation would probably continue even under lower duties. Moreover, as international trade develops in these materials, this country is more likely to be a net exporter than a net importer. 3. TAR-ACID RESINS