The Economic System of Socialism (ESS) was an economic policy implemented in East Germany between 1968 and 1970, which was introduced and led by the country's autocratic leader, Walter Ulbricht. It focused on high technology sectors in an attempt to make self-sufficient growth possible. Overall, centralized planning was reintroduced in the so-called structure-determining areas, which included electronics, chemicals, and plastics. Industrial combines were formed to vertically integrate industries involved in the manufacture of vital final products. Price subsidies were restored to accelerate growth in favored sectors.