On the other hand the economic significance of the Negro to-day is tremendous. Black Africa to-day exports annually nearly two hundred million dollars' worth of goods, and its economic development has scarcely begun. The black West Indies export nearly one hundred million dollars' worth of goods; to this must be added the labor value of Negroes in South Africa, Egypt, the West Indies, North, Central, and South America, where the result is blended in the common output of many races. The economic foundation of the Negro problem can easily be seen to be a matter of many hundreds of millions to-day, and ready to rise to the billions tomorrow. Such figures and facts give some slight idea of the economic meaning of the Negro to-day as a worker and industrial factor. "Tropical Africa and its peoples are being brought more irrevocably every year into the vortex of the economic influences that sway the western world."[113] What do Negroes themselves think of these their problems and the attitude of the world toward them? First and most significant, they are thinking. There is as yet no great single centralizing of thought or unification of opinion, but there are centers which are growing larger and larger and touching edges. The most significant centers of this new thinking are, perhaps naturally, outside Africa and in America: in the United States and in the West Indies; this is followed by South Africa and West Africa and then, more vaguely, by South America, with faint beginnings in East Central Africa, Nigeria, and the Sudan. The Pan-African movement when it comes will not, however, be merely a narrow racial propaganda. Already the more far-seeing Negroes sense the coming unities: a unity of the working classes everywhere, a unity of the colored races, a new unity of men. The proposed economic solution of the Negro problem in Africa and America has turned the thoughts of Negroes toward a realization of the fact that the modern white laborer of Europe and America has the key to the serfdom of black folk, in his support of militarism and colonial expansion. He is beginning to say to these workingmen that, so long as black laborers are slaves, white laborers cannot be free. Already there are signs in South Africa and the United States of the beginning of understanding between the two classes.