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THE ECONOMIC JOURNAL
the hands of one, a tendency counteracted by what, with
reference to abstract theory, may be described as accidental
circumstances.
(2) The carrying trade tends to fall into the hands of that
nation the volume and weight of whose exports are greatest.
(3) An improvement in productivity tends to deprive a country
of a share in the carrying trade.
(4) Improvements in means of production redound in general,
and in the abstract, to the good of the importing people only.
These propositions appear to be, not indeed incorrect—as
defined and qualified in the context—yet unimportant. Con-
sidering, however, the solidity of the rest of Mangoldfs work, it
may well be that one specially interested in the problem of the
apportionment of the carrying trade would discern more in this
last section than the present writer, after taking a reasonable
amount of trouble, has been able to find.
(4) Auspitz and Lieben.—In that portion of the Théorie des
Preises which treats of international trade, the subject is en-
riched with important propositions and embellished with splendid
illustrations. Perhaps the most valuable result due to the authors
is the general geometrical proof that a nation may benefit itself in
certain cases by an import or export tax. The construction by
the aid of which they have discerned this theorem more clearly
than their predecessors1 is much the same as that which has been
employed in the earlier pages of our mathematical part : down to
the introduction of complicated curves corresponding to organic
changes in trade.2 But there is one important difference between
even our simpler constructions and theirs : that theirs are re-
stricted to a small part, ours are applicable to the whole volume of
trade. Their abscissa represents a real article, one out of the many
items in international trade ; their ordinate represents money,
the marginal utility of which is properly considered as not
varying with the amount consumed of a single article. Each of
our co-ordinates on the contrary represents not so much actual
commodities or money, as an ideal article typical of the total
volume of trade ; used to suggest conclusions which may be
verified by the algebraic analysis proper to the real case of
numerous exports or imports.8 Accordingly their supply- or
offer- curve is never inelastic in our sense of the term ;4 it
continually ascends like the curve O E in the annexed figure ;
since, if money have a constant utility-value, for a higher price
1 Théorie des Preises, fig. 74. 2 Ante, pp. 426-485.
3 Ante, pp. 424, 442. 4 Ante, pp. 428, 429.