One would not be justified in a book of this nature in even briefly outlining the use of the income tax as it is found in more than fifty countries outside the United States. In some of the countries it forms an important part of the revenue system, while in others its role is comparatively insignificant. The significant feature is that the tax is one of the newest systems of securing revenue, and that its place in the different countries where it is being used is becoming more extended and secure. A brief mention of some of the countries where the tax is playing an important part will reveal the fact that it is found in new as well as in firmly established governments, and in radical as well as conservative states.

An outline has been given of the Prussian income tax system because it represents one of the best organized forms of income taxation, yet income taxes have been in use in the minor German provinces much longer than they have been found in Prussia. In these, as in most of the continental taxes, low exemptions and minute classifications are found.

The English colonies have followed the lead of the Mother country, and have made extensive use of the income tax. The different states of Australia have well-developed and important income taxes. The Federal government of Canada has not made such an extensive use of this form of revenue as some other countries, although income taxes hold an important place in some of the provinces. These taxes resemble the British plan of comparatively high exemptions, with no definite scale of progression. India has a systematic plan which somewhat resembles the British.

Italian and Austrian fiscal machinery very early made a place for income taxes, while they have for a number of years played an important part in the revenue systems of Norway, Switzerland, Hungary, Russia, Japan, and the Philippines. France adopted the tax in 1914, but the outbreak of the war interfered with putting it into effect.

Many other examples might be given of the use of income taxes, but enough have been cited to warrant the conclusion that their use is very general. More than half of the people of the world are now living under the domain of income taxes. These taxes are not used as extensively by Federal governments as by the smaller political divisions, although central governments have shown a tendency to favor the tax. The comparative newness of the tax is another general characteristic - a large majority of present systems having been introduced since the beginning of the present century. After this survey of the tax abroad the situation in the United States will be of interest to American students.