20 



PRODUCTION 



of discarded animals which are destined for slaughter as food in the 

 importing country. 



In estimating the net balance of trade of a given country in 

 animal foodstuffs together with the materials used expressly for 

 their production, the most convenient common denominator for 

 all the products concerned is that of values, and this is used occa- 

 sionally below ; though this method cannot safely be used for 

 comparing the position in one period with that in another, it has 

 some value for the purpose of affording a summary view at a stated 

 time. When comparing the position of different countries in the 

 same period by this method, it must be remembered that the value 

 of the given consignments of commodities are, on the average, 

 lower in the exporting than in the importing countries, so that the 

 total value of the recorded exports of a certain class of products 

 will be smaller than that of the recorded imports. It is im- 

 possible, however, to expect refined accuracy in international 

 trade returns ; it happens even that not inconsiderable discrepancies 

 appear between the total recorded export? and the total recorded 

 imports of the same article, even when these are expressed in 

 quantities. 



