Health care in Greece has historically developed into a multi-tier system, a mosaic of public and private providers of services covering the members of occupational social insurance organizations. In 1983 PASOK's socialist government established a unified National Health System. The aim was to arrest the growth of the private sector and promote the public sector to a dominant position. The socialist legislation has recently been reviewed by a conservative government that aims at a competitive mixed market of public and private providers. The growth of private health care, however, is not solely a matter of political support but also of new opportunities for profitable investments that arise from a shrinking public sector under economic and fiscal constraints.