Hebrew for going down. This refers to emigration from Israel. Yerida became a salient issue of public concern in the late 1970s and continued into the 1980s despite uncertainty as to its exact dimensions and the fact that during each of the major waves of aliya, there was also emigration. Nevertheless, yerida was seen as something of a measure of well-being in Israel.
Historical Dictionary of Israel. Bernard Reich David H. Goldberg. Edited by Jon Woronoff..