"The advantages of a tax on house rentals," said the commission, "can be easily stated. It is clear, almost impossible of evasion, easy of administration, well fitted to yield a revenue for local uses, and certain to yield such a revenue. It is clear, because the rental value of a house is comparatively easy to ascertain. The tax is based on a part of a man's affairs which he publishes to all the world. It requires no inquisition and no inquiry into private matters; it uses simply the evidence of a man's means which he already offers."[13] If this tax were to be given it would be possible to wipe out all the tax on incomes from "profession, trade, or employment," to abolish the existing assessments on personal property. The effects would be far-reaching. If loans of money are free from taxation, the purchasing power of money in the same degree must diminish, which simply means that the purchasing power of farms and products of farms for money must to the same extent increase; hence, the borrower on bond and mortgage will not be subject to double taxation--first, in the form of increased rate of interest, and then in taxation of his real estate--and hence the farmer or landowner who is not in the habit of either lending or borrowing money will find his ability to meet additional taxation on his land increased in additional value of land and products of land in proportion as the tax is removed from money at interest. Also, the exemption of the products of farms and things consumed on farms from taxation will give a corresponding increased value to compensate for the "building-occupancy" tax. Tenants controlled by all-pervading natural laws can and will give increased rents, if their personal property is exempt primarily from taxation. The average profits of money at interest or of dealings in visible personal property free from taxation can not exceed, for any considerable length of time, the average profits of real estate, risk of investment and skill in management taken into consideration; and therefore the real pressure of taxation under the proposed system will finally be, like atmospheric pressure or pressure of water, on all sides, and by a natural uniform law executed upon all property in every form used and consumed in the State. Persons must occupy buildings and business must be done in buildings, and through these visible instrumentalities capital can be reached by a rule of fractional uniformity, and by a simple, plain, and economical method of assessment and collection. [Footnote 13: Massachusetts Report, p. 106.] This building-occupancy tax, or tax on rental value, does not preclude a supplementary tax on corporations.