Article 23 of the Constitution guarantees the right of property, and the article 23 states that expropriation, use, or restriction of private property from public necessity and compensation are governed by law but just compensation must be paid. The amount of compensation is estimated by making other adjustments on compensation precedents in the neighborhood, making adjustment of time, location, and physical factors on the GALP (Government announced land price) of the benchmark site, as of prior date to the recognition notice date of the public project. Therefore, the exclusion of betterment may depend on how to calculate time GALP applied to, time adjustment, and other factors.
According to the「Act on the Acquisition of Land, etc. for Public Works and the Compensation Therefore」the time of compensation estimate is assumed as the recognition date of the public project. If the date of zoning-designation is assumed as the recognition date, the exclusion of betterment seems to be executed in theory. However, in practical the GALP eventually includes betterment since the land prices in the accommodated district have elevated and speculation has been terrible as the public project has leaked out from much earlier than the date of zoning-designation. Consequently, it is necessary that the GALP announced one-year earlier than the date of zoning-designation is applied to estimate of the compensation for more positive exclusion of betterment.
Next, making time adjustment has two methods, to apply the GALP and PPI (Producer price index). Again, time adjustment by the GALP has two methods, to use the benchmark in neighboring 'Si' and 'Gun' and to use the average rate of land inflation nationwide, but the latter method is adequate for more positive exclusion of betterment.
Time adjustment for estimating other adjustments by compensation precedents in the neighborhood is based on the average rate of land inflation nationwide, and applying actual transaction prices by Real Estate Transactions Reporting System; then, exclusion of betterment and propriety of the amount of compensation will be further promoted.
Betterment should be excluded but dissatisfaction on compensation of the accommodated will become high. This is because prices of lands neighboring the project will highly increase and owners of lands neighboring can be privatized unearned incomes from it. It is necessary to seek a means to redeem development profits of neighborhood so as to promote fairness between the accommodated and owners of neighboring lands and to settle excessive compensation.