24 THE A B C OF TAXATION to take for public purposes the future increase in ground rent will be interested to note what an opportunity for putting such a plan in operation in Boston is shown by the above figures to have been lost twenty years ago. X. —Corresponding Exemptions In any calculation of the effect of the imposition of all taxes upon ground rent, it must be borne in mind that the landlords, who are the owners of the ground rents, also own buildings and other improvements upon the land, together with a large per cent of the personal property, so that they, as a class, would find the additional tax upon their land offset by the exemption of buildings and personal property. XI. —The Exemption of Assessed Values One reason why, under a just system of taxation, large-hearted landlords would cheerfully offer their necks to the tax yoke is the fact that so far as concerns their investment in land most of them are now privileged to be entirely exempt. In other words, the present tax is not a tax burden upon them, even though this fact is not to their prejudice. But while it is true that the capitalised value of any tax on land is deducted from its selling price, and that any purchaser, after the tax is once imposed, gets his land tax free,* so that the landowners of Boston who have bought their holdings since the present tax rate was reached are practically exempt from taxation, it is also true that *A tax, as a first lien, is practically a first mortgage to which any regular mortgage must be second. The effect of the tax in the first case and the mortgage interest in the second case upon the selling value of land is exactly the same. When the State imposed a tax of $10 upon a lot of land hitherto untaxed and worth $1,000, the effect upon the selling value was the same as though it had taken a first mortgage of $200, leaving to the owner as the selling value an equity of $800.