SIGNIFICANT FEATURES OF MIGRATION 31 nonimmigrant and is now leaving after having been in this country less than one year, or he is an alien resident of the United States leaving for a temporary sojourn abroad. It should be noted that the definition of ‘‘immigrant” for purposes of the quota restriction acts of recent years differs somewhat in scope from the traditional meaning of the term as above defined. Ordinarily in official and popular use, the terms immigrant, emigrant, immigration, and emigration refer to the relatively permanent immigrant or emigrant and exclude from consideration the nonimmigrant and nonemigrant groups; and, as a rule, that practice is followed in this monograph. However, it should be noted that for some purposes the citizen and nonimmigrant alien elements should not be ignored. Unless the arrivals and departures of these groups balance—and they do not—they should logically be included in a study of the contributions which migration makes to population. Also, in our present inquiry, the reaction to employment conditions of the aliens arriving or departing temporarily from our shores may be as significant as the fluctuations in the movements of immigrants and emigrants proper. In fact, it would seem reasonable to expect that the volume of migration of workers who come for only a temporary residence would be especially sensitive to changing conditions of employment. In the following pages, the terms tmmigrants and emigrants refer ordinarily to those relatively permanent alien arrivals and departures officially designated as immigrants and emigrants; the terms alien arrivals and alien departures include, in addition, the nonimmigrant and nonemigrant group, respectively; and the terms total arrivals and total departures are inclusive of all recorded arrivals and departures of both citizens and aliens. In some instances the term permanent has been used for immigrants and emigrants and temporary for the nonimmigrants and nonemigrants; but these terms should not be interpreted too literally, as the classification is based upon the declared intention, and intentions may be either misstated or subsequently changed. The arriving alien who declares an intention of establishing a permanent residence in this country may find conditions less agreeable than expected and emigrate within a few months. The fact that in the seventeen years from July 1, 1907, to June 30, 1924, the recorded total of nonimmigrants was only 2,485,789, while that of nonemigrants was 3,097,567, indicates either that thousands of incoming aliens declare an intention of permanent sojourn but change