Segak. — On the Trade and Public Debt of N.Z. 117 



Art. VIII. — Remarks on the Trade and Public Debt of Neio 



Zealand. 



By H. W. Segar, M.A., Professor of Mathematics, Uni- 

 versity College, Auckland. 



[Read before the Auckland Institute, ISth August, 1902.] 

 Plates XI.-X1V. 



In tables of the trade, revenue and expenditure, public debt, 

 &c, for any country, it is usual to present the value in terms 

 of some monetary unit — e.g., the sovereign or pound sterling. 

 Now, the sovereign represents a fixed amount of gold, but not 

 a fixed exchange value. The extent to which the sovereign, 

 or any given number of sovereigns, will purchase commodities 

 in general varies considerably from time to time. Conse- 

 quently a man with a fixed income — that is, with an income 

 of a fixed number of pounds — may be really much better or 

 much worse off at one time than at another because of the 

 variations in the purchasing-power of his income. The trade 

 of a country may be progressing well and soundly during a 

 period for which bare statistics of values may appear to indi- 

 cate a sickly and declining condition of trade, and trade may 

 be really languishing when these statistics indicate continued 

 progress. Before we can properly compare monetary statis- 

 tics of one period with those of another we must take into 

 account the valuations in the purchasing-power of money, 

 remembering that the value of any sum of money is the 

 amount of commodities which it will purchase at the time. 



Index Numbers. 



This we are enabled to do roughly by means of index 

 numbers. We need not enter on a general description and 

 discussion of these in this place ; let it suffice to say that their 

 purpose is to represent the average prices of commodities at 

 different periods, the average prices being directly proportional 

 to the index numbers, and the purchasing-power of money 

 consequently inversely proportional to them. The following 

 table represents Sauerbeck's index numbers for the years 

 1880-1900 :— 



