Some difficulties have arisen in the use of the special assessment. A number of these difficulties constitute the chief objections that Europeans have to the principle. One which quickly suggests itself is that of making an assessment in proportion to the increase in property value, and in determining the proper district over which to make the levy. The paving of a street benefits not only abutting property, but also property in the immediate vicinity. An expression commonly used is, "only a block from a paved street." Evidently property in the vicinity of a paved street is enhanced in value, even though an exact measure of the increase may be difficult. The base upon which the levy is to be made is also troublesome at times.
Frontage is often used, but this is sometimes so obviously unjust that area or selling value may also be considered.
It has been objected, frequently, that the use of the special assessment is dangerous because it may compel the property owners to meet the expense of improvements which the nonproperty owners may desire, or that exorbitant assessments may be placed by unscrupulous politicians under the guise of conferring a benefit. In so far as the assessment is measured by the actual benefit to property, the first objection can have but little weight. The improvements will mean increased differentials which will be reflected in higher rents, so that much of the burden will rest on the nonproperty owning class if paying for a benefit actually received can be called a burden. Much fraud and injustice have arisen in making special assessments, and there is no doubt that the amount exacted has often been far in excess of any benefits accruing to property. Anyone familiar with the Tweed rule in New York City has sufficient evidence of this. The decision of the courts, however, that any exaction in excess of benefits is taking of property without just compensation, has done much to alleviate this difficulty.
The principle of the system, in spite of the numerous difficulties, has appealed so much to the sense of justice that it is being more firmly embedded in municipal fiscal policies. If a public improvement to the property of one individual gives an increase in value which does not come to the general public, it is but just that some return should be made for this increased value. Great care, however, should be exercised by the administrative authorities in fixing the assessment district and in determining the base and amount of the assessment, so as to alleviate as much as possible injustice and inequality. This admonition applies, however, not only to special assessments, but to other forms of revenue as well.