§ 3. Specific and ad valorem rates. Before entering upon the history of the American policy let us make clear the mean ing of certain technical terms and explain certain methods that are frequently referred to.
Rates (and duties) may be either specific or ad valorem. Specific duties are those that are calculated and levied ac cording to some physical test, as so much per pound, per yard, per hundred-weight, or per ton. Ad valorem duties are those that are calculated and levied according to the value of the goods (usually as it was at the place of shipment), determined by an assessor, by invoice of sale, by statement of the importer under, oath, eta. The actual duty collected on any article may result from various combinations of the two rates (as, to take an actual example, $4.50 a pound and 25 per cent ad valorem on cigars and cigarettes) or ad valorem with a minimum valuation so that on the cheaper goods the rate is specific.
Specific rates are more easily applied in administration, not offering the temptation to undervaluation and misrepresen tation that ad valorem rates do ; on the other hand, specific rates do not adjust themselves to price changes as ad valorem rates do. If the prices of goods go up the specific rate is relatively less and affords less of "protection" to the domestic producer; whereas if prices go down (as, in general trend, the prices of manufactured goods have done most of the time) the specific duties are relatively greater. To take a historical example, the specific rate of 6% cents a yard on cotton goods in 1816, which was at first in fact only about 25 per cent, within a few years became about 75 per cent and absolutely prohibitive. For this reason specific rates have most often been used in acts intended to increase the "protective" duties and often as a device for immediately raising rates; while ad valorem rates have been more often used in acts prompted by the desire for less drastic exclusion and for a more adequate revenue; but there is no essential connection between the protective policy and specific rates. Indeed, in the period from 1897 to 1909, when most prices were rising, many of the specific rates under the Dingley Act, intended to be strongly protective, afforded less and less § 4. Some technical features of the tariff. All goods not subject to duties are said to be on the free list. It is custom 2 It is evident that it is only through ad valorem rates that it is possible to compare the average rate of duty for one tariff act with that for another. As, however, every tariff act is made up of both specific and ad valorem duties, it is only at the end of the year that an average ad valorem rate can be estimated by comparing the total of duties collected with the total estimated value of the goods imported.
Average ad valorem rates are estimated in this way both on the dutiable goods alone, and on all goods, free and dutiable combined. There may be an element of error, even of misrepresentation, in such estimates. They do not give the simple test of the relative height of duties or of the degree of "protection" that we might at first suppose. Just to the extent that a new and higher rate really operates to exclude imports (and thus is protective in its effect) the goods subject to that rate cease to form part of the total imports. For example, if the average rate of duty were 25 per cent, and a 50 per cent rate on an article were increased to 75 per cent, it is possible that this rate would prove to be absolutely prohibitive. This raise of rate, therefore, would tend to reduce the average rates collected on all dutiable articles. Changes in general conditions of industry from causes quite apart from the tariff may result in shifting the proportions of imports that are dutiable so that the average rates go either up or down while the tariff law has re mained unchanged on the statute book. A failure to consider these and related facts leads to much confusion in popular and political discussion of the tariff.