A nation exports its goods and services to enable it to supply its wants for the products and services of other lands. The United States is no exception. Merchandise imports follow closely the trend of exports, varying with the business cycle, but ex panding with the progress of the national economy. Average yearly imports of merchandise were valued at $52,359,000 during the decade 1790-1800. They had doubled in value by the fourth decade of the 19th century, more than doubled again in the ten years before the Civil War, and doubled a third time in the 187os. The $1,000,000,000 mark was first reached in 1903 and the maximum of $5,278,000,000 was achieved in 1920. Between 1925 and 1929 merchandise imports exceeded $4,000,000,000 each year. The depression which began in late 1929 saw imports of merchandise fall off to less than $1,323,000,000 dollars in 1932. Recovery began in 1933 and continued through 1937 when corn modity imports were valued at $3,010,000,000. Changes in the price level explain a part of the changes recorded in these figures as was noted for the export date. (See Table XIV.) A further consideration of importance is the fact that merchan dise imports are divided into the sheep and the goats, those which are admitted into the country free and those upon which customs duties are levied. Many shifts have taken place in the relative proportion of these two classes during the history of the United States. Less than 6% of all merchandise imports on the average were free of duties in the decade 1821-3o, while over 38% came in duty free during the following ten years. At the close of the 19th century about 46% of total imports came in on the free list, while 61% were free by 1920, a ratio which held with minor variations up to the depression era of the '3os. By 1933 the ratio of free imports to the total was 63%, while by 1936 it had fallen to 57%. By 1938 it had recovered to 6o%.
The chief significance of these shifts in the proportion of duty free imports to the total lies in the fact that they reflect changes in the structure of the economy of the United States.
The upward trend in the proportion of duty free imports has paralleled a trend in commercial policy towards higher and higher import duties which has only recently been halted. Thus the ex planation lies in the shifts in the kinds of goods imported rather than in any liberalization of the import restrictions.
A selected group of thirty commodity classifications, including the leading items (Table XV), made up over 75% of total mer chandise imports in 1937, the high point of recent years. Crude
rubber was first on the list that year with 1,339,000,000lb. im ported, valued at nearly $250,000,000. Cane sugar ranked second, followed in order of value by coffee, newsprint, vegetable oils and fats, raw silk, and tin, each of which exceeded $100,000,000 in value. Contrast the rank of these items with those which pre dominated a decade earlier. Raw silk was definitely the leader, followed in order by crude rubber, coffee, cane sugar, newsprint, petroleum and products, hides and skins, furs and manufactures, and fruits and nuts. Fluctuations in raw silk imports illustrate what is happening continuously in a dynamic economy for many other commodities. The United States imported 24,000,000lb. of raw silk on the average in the years 1910-14. By the period 1921- 25, the average had risen to 52,000,000lb., a trend which carried the average to 75,000,000lb. for the years 1926-30. The depres sion years 1931-35 reduced this average very little to 70,000,000lb. but since 1935 there has been a steady shrinkage to 60,000, 000lb. in 1936, 58,000,000lb. in 1937, 55,000,000lb. in 1938, and 22,000,000lb. for the first six months of 1939. Threats of a new artificial textile fibre, reputed to be superior to silk in elasticity and durability, make the future of raw silk imports look black indeed. From fifth place in 1938 it may drop to a very minor position in a few years. Other products, perhaps not even known as yet, may spring into prominence, dominate the stage for a few years, and give way to still other commodities. (See Table XV.) Leading Commodity Exports.—The trend of merchandise exports reflects the same dynamic forces which are continuously reshaping the contour and content of the economy of the United States. In the pre-war years 1910-14, unmanufactured cotton was the number one item on the list of merchandise exports. Ma chinery was second in rank, followed by packing-house products, petroleum and products thereof, and wheat and flour. Just before the depression, cotton continued in first place, but petroleum and its products had taken second place from machinery which occu pied third place, followed by automobiles, parts and accessories, wheat and flour, and packing-house products. The outstanding change in this period was the rise of the automotive industry. Exports from this industry which averaged but $24,000,000 be tween 1910 and 1914 had risen to $406,000,000 on the average for the years 1926-30. The post-depression year 1937, a year of business strength generally, showed exports of machinery to hold first place with petroleum and its products in second position. Cot ton had dropped to third place with exports of $369,000,000, less than half of the 1926-30 average. Automobiles, parts and accessories were in fourth place followed by iron and steel mill products. (See Table XVI.) The outstanding fact revealed by analysis of the merchandise export statistics of the United States is the growing shift in em phasis from agricultural products to manufactured products. This shift, which is exactly opposite to that noted in the import sta tistics, reflects the movement of the underlying economic struc ture, the increasing industrialization of the national economy.