138 TRADE BETWEEN 1900 AND 1913 
given above records the main variations with a precision 
sufficient for our purpose. 
The correlation of all these factors into a complete statistical 
picture will now be possible for our period. The comparison of 
export and import prices, the relation known as net barter terms, 
gives a comparison that measures approximately the changing 
margin of advantage in prices received by Australia or Great 
Britain from year to year. The smoothed moving-average curve 
shows during the earlier years a gradual rise of the net terms in 
favour of Australia which has to be compared with the curve for 
export prices in Fig. XII. Very little advantage is indicated 
as between the beginning and the close of the period, that is to 
say that the price-levels have been automatically adjusted over 
the whole period as the theory of prices would lead us to suppose. 
A net increase in the return to labour, at least for those occupa- 
tions for which the wage statistics are collected, is indicated by 
the curve for wages which tends slowly but steadily upwards 
right through the piece. But the consideration of the physical 
volume of goods figuring in overseas trade, taken in conjunction 
with the import. and export price indices, i.e. the gross barter 
berms, reveals a very different state of affairs. There is clearly 
a gain as shown by this curve of approximately 30 per cent. for 
Australia during the early years of the period followed by a 
steep decline of over 40 per cent. by the end of the period. Here, 
then, is the key to the growing financial tension of 1913; and 
the crises of 1903, 1907-8, and 1912 fall into place as mere phases 
in the steadily increasing disadvantage in trade which was the 
chief result of the growing burden of overseas debt.