It is to be noted that most of the German laws are retroactive, since they apply not merely to future value increases, but to some of those that occurred before the law was enacted. Thus, the Hamburg ordinance measures the increases from the last sale, no matter how long ago that transaction took place. The imperial law uses the same starting point, except in cases where the last sale occurred before 1885. Accordingly, a man who had in 1880 paid 2500 marks for a piece of land which in 1885 was worth only 2000 marks, and who sold it for 3000 marks after the law went into effect, would pay the increment tax on 1000 marks,--unless he could prove that his purchase price was 2500 marks. In all such cases the burden of proof is on the owner to show that the value of the land in 1885 was lower than when he had bought it at the earlier date. Obviously this retroactive feature of the German legislation inflicts no wrong on the owner, since it does not touch value increases that he has paid for. Indeed, the value of the land when it came into the present owner's possession seems to be a fairer and more easily ascertained basis from which to reckon increases than any date subsequent to the enactment of the law. On the one hand, persons whose lands had fallen in value during their ownership would be automatically excluded from the operation of the law until such time as the acquisition value was again reached; on the other hand, those owners whose lands had increased in value before the law went into effect would be taxed as well as those whose gains began after that event; thus the law would reach a greater proportion of the existing beneficiaries of "unearned increment." Moreover, it would bring in a larger amount of revenue. The British law formed a part of the famous Lloyd-George budget of 1909. It taxes only those increments that occur after its enactment. These are subject to a tax of twenty per cent. on the occasion of the next transfer of the land, by sale, bequest, or otherwise.[97] In some cases this arrangement will undoubtedly cause hardship. For example: if land which was bought for 1,000 pounds in 1900 had fallen to 800 pounds in 1909, and were sold for 1,000 pounds in 1915, the owner would have to pay a tax of twenty per cent. on 200 pounds. This would mean a net loss of forty pounds, to say nothing of the loss of interest in case the land was unproductive. It would seem that some compensation ought to be given here; yet the rarity of such instances, the administrative difficulties, and the general advantages of this sort of legislation quite conceivably might forbid the conclusion that the owner was made to suffer certain injustice. The compensating social advantages of the increment tax as well as of other special taxes on land, will receive adequate discussion presently. _Transferring Other Taxes to Land_