Subject(s): India in Economic policy in 1980-1991 in Mathematical models. -- Characteristics of LDCs, approaches to planning, plan preparation and implementation -- nature and type of models, historical perspective of planning in India, process of planning and two sector model- singe sector model, two sector model, first five year plan -- First six five year plans -- Four sector model, models related to the third five year plan- Sandee's long term planning model, Chakaravarty model, annual plans -- Fourth plan : Economic division's exercise, perspective planning division's exercise -- Model for fifth five year plan, model for the production of food grains - production performance, food targets and achievements under the plan, model for food grains production -- Models for the economy and conclusion , model for sixth five year plan