Environment and Planning B: Planning and Design 1994, volume 21, pages 259-272 The implications of drastic change for infrastructure planning goals: immigration stress in Israel E Feitelson, I Salomon Department of Geography, The Hebrew University of Jerusalem, Mount Scopus, Jerusalem, 91905 Israel Received 29 October 1992; in revised form 22 August 1993 Abstract. Most infrastructure planning assumes continuous dynamics. This paper is about the case where demand grows as a result of drastic, noncontinuous exogenous change and, in partic- ular, sudden massive immigration. Through a discussion of the current issues facing Israel in absorbing the recent immigration wave, the authors argue that drastic change leads to a shift in planning criteria. Economic development and basic requirements take precedence over welfare maximization. Such a shift requires that different models be developed and used. 1 Introduction The dynamics of social, economic and political systems are manifest in regional changes. Thus, regions may grow, decline, or remain in a stagnant situation. Regional growth or decline imply that the demand and supply of infrastructure services are in disequilibrium. The extent of the discrepancy between demand and supply determines the pressure for infrastructure modifications, and is affected by the pace of changes taking place. Modifications in the supply of infrastructure services usually require a long lead time for planning and implementation. Thus, the provision of infrastructure is almost always based on long-term forecasts. Such forecasts are usually based on assumptions of long-term continuous economic, technological, social, and political processes within the regions, in competing regions, and on larger spatial scales (national, international, or global). Even under such assumptions infrastructure planners need to account for the high levels of uncertainty typical of many such forecasts (Haynes and Krmenec, 1989; O'Sullivan et al, 1979). Amost no analytical attention has been given to the implications of situations of rapid change, which are inherently uncertain and do not allow long lead times for infrastructure planning. In this paper we address this lacuna. Rapid change may occur when a sudden political change takes place (such as a revolution, a war, a partition, or unification), a natural disaster devastates much of the infrastructure, or a massive immigration or emigration takes place. In such cases either demand for infrastructure services changes dramatically, or the supply is disturbed, creating sudden and wide imbalances between supply and[ demand. Two types of situation of rapid change can be discerned. The first is cata- strophic change, or complete discontinuity with previous trends, institutions, and allocation mechanisms. The second, in which we are interested, is labeled 'drastic change'. It occurs when the pace of change is very fast, but does not involve a total discontinuity with the past. Still, it imposes large-scale pressures on the incumbent system. One recent example of drastic change is the reunification of Germany, t Earlier versions of this paper were presented at the Anglo-Israeli Regional Science Associa- tion workshop on local and interregional migration, in Shefayim, Israel (3-5 June 1991), and at the 15th International Symposium of the European Faculty on Land Policy and Infra- structure, in Delft, The Netherlands (11-12 November 1991).