August 1, 1919.] 



THE INDIA RUBBER WORLD 



615 



Price quotations were secured for five representative varieties 

 of the former class and for four of the latter. In the calen- 

 dered rubber clothing class the following have been included*: 



3. Jeans (dull finished). 



4. Smgle-text. 



5. Double-te.tture cowboys. 



Under double and single texture clothing have been chosen : 



VVooIe 



4. Wo 



METHODS OF MAKING CHARTS. 



In order to determine the relation between crude rubber prices 

 and those of rubber products, and in order to define further 

 the bearing of the price situation in the rubber industry as 

 a whole on that in other industries, a uniform method of aver- 

 aging price fluctuations was resorted to, and the method used 

 in all the bulletins of the present series was applied to rubber. 



After selecting representative articles to typify the various 

 classes of crude rubber and rubber products, monthly quotations 

 were secured from trade journals and from members of the trade 

 for the period 1913 to 1918. (See Tables III and V.) Prices 

 of the more important grades' of crude rubber, as well as of the 

 more important rubber goods, were then individually averaged 

 on the basis of their pre-war level and charted. Since the in- 

 quiry centers about the effect of the war upon prices, the charts 

 were made to show the movement of prices away from the pre- 

 war level. This effect was produced by treating the average of 

 the actual prices for the twelve months preceding the outbreak 

 of the war (July, 1913, to June, 1914) as equal to 100, and re- 

 ducing the actual prices for each month from January, 1913, to 

 December, 1918, to the form of relative prices on that scale. 

 Thus, for example, if the selling price of a given unit of a product 

 averaged $2 in the year ending June 30, 1914, and fell to $1.80 

 in 1915, the relative price of that product for that month would 

 be 90; if the price rose to $4 in June, 1918, the relative price 

 would be 200. 



The numerous price charts scattered throughout this bulletin, 

 as well as through the other studies of the series, were drawn 



•■Single 



on this uniform scale,' and under this arrangement all the relative 

 price charts in the present series of price histories are com-' 

 parable with one another. 



For those who are interested not merely in the fluctuations 

 of particular commodities such as rubber tires or rubber cloth- 

 ing, but also in the price fluctations of the class of rubber 

 products as a whole, "index numbers" are provided. A simple 

 average of commodities sold — some by the dozen, some by single 

 units, and some by the foot, as is the case with hot-water bottles, 

 rubber tires, and rubber hose, respectively— would obviously be 

 of little value. Therefore in making index numbers, each in- 

 dividual commodity is "weighted" by multiplying the monthly 

 prices from 1913 to 1918 by the amount of the commodity pro- 

 duced in the United States in the year 1917, plus imports. In 

 the case of crude rubber, since there is virtually no domestic 

 production, the imports for 1917 are used as the weighting 

 factor. The year 1917 was selected as the weighting year so 

 that war-time conditions could be reflected. Figures for 1918 

 may have been more typical of the war situation, but such data 

 were not available for many commodities when the studies were 

 being written. 



Table II.— IMPORTS OF CRUDE RUBBER INTO THE UNITED 



STATES, 1913 TO 1918.» 



1913. 1914. 1915. 1916. 1917. 1918. 



I'lantations ...long tons 23,967 35,326 61,085 85,287 134,946 133,167 



Paras' 18,481 19,466 32.017 22,490 25.225 20,081 



Africans (* (») (») (») 3,330 730 



Centrals <») («) (») (») 898 762 



Guayule 2,756 850 2.654 435 1,863 1,329 



Manigoba and Matto 



Grasso (') (S) (') (') 800 146 



All other 6,276 5,084 7,068 6,831 



Total 51,480 60,726 102,824 115,043 167,062 156,215 



* These samples of rubber clothing arc designated by their respective 

 trade names and have been selected with the aid of The Rubber Associa- 



'' The one exception to this statement is the case of dyestuffs, where 

 the extraordinary rise in prices necessitated a change in scale. , 



" Since the amount of crude rubber re-exported from the United States 

 IS practically neglicible, the figures presented in the above table may be 

 taken as analogous to our rubber consumption. Data from The Iniiia 

 Rubber World. 1917. ' 



• Caucho has been included in Paras. 



prin 



Rubber Products and "All Commodities." 

 By Months, January, 1913, to December, 

 18. (Average Quoted Prices, July, 1913, 



June, 1914 = 100.) 



Figure 3. Relative 

 Solid Rubber (36 

 Tread (30 by 3^) 

 1913, to December, 

 Prices, July, 1913, 



5); Pneumatic Pi-uh 

 -By Months, January 

 918. (Average Quotei 

 June, 1914=100.) 



Figure 4. Relative Prices of Mechanical 

 Rubber Goods: Conveyor Belting; Water 

 Hose.— By Months, January, 1913, to De- 

 cember, 1918. (Average Quoted P'rices, July, 

 1913, TO June, 1914 = 100.) 



