138 VALUATION, DEPRECIATION AND THE RATE-BASE 
The fact is evidently being recognized in Idaho as elsewhere, 
that the service rendered should always be zoo per cent good 
even though rendered by a plant whose physical parts are per- 
ishable and that if a roo per cent valuation for rate purposes is 
fair when the plant is new it is equally fair when the plant is old. 
Wisconsin Railroad Commission on Investment as the Rate- 
base. — The view which the author takes relating to making the 
necessary original cost and not “value »” the starting point 
when rates are to be fixed finds some support in the following 
statement by the Wisconsin R. R. Commission in the City of 
Appleton Case (Wis. R. C. R,, Vol. 5, p. 220). 
« For rate-making purposes the actual total investment, sub- 
ject to certain qualifications, seems to be the basis for deter- 
mining the reasonableness of the charges that may be exacted 
of the public for the services rendered or product furnished in 
certain jurisdictions. Of course where such information is not 
available, the reasonable value of the investment would have to 
be ascertained by some method of appraisement, and in such 
event the ¢ actual total investment’ doctrine would be inappli- 
cable.” 
Appraisals for Taxation Purposes 
The Taxation Value. — The tax value is usually intended to 
bear some definite relation to the market value. In some of 
the older Eastern cities of this country the tax value is intended 
to represent the full market value. Generally, however, this is 
not the case. Real estate will usually be found to be valued 
for taxation purposes at from so to 75 per cent of its market 
value and personal property sometimes still lower. 
The appraiser of tax values is therefore interested in market 
value and must give consideration to all the elements that go to 
establish market value, such as supply and demand, earning 
capacity present and prospective, rate of appreciation and the 
like. But this is a subject which is foreign to the purposes of 
this volume and may be dismissed with the above broad state- 
ment.