World Dynamics

1970 conditions accumulation agricultural land assumed assumptions behavior billion birth rate normal birth-control program BRFM BRN1 capital investment CAPITAL UNITS CAPITAL UNITS/PERSON CAPITAL-INVESTMENT DISCARD capital-investment multiplier capital-investment ratio CAPITAL-INVESTMENT-IN-AGRICULTURE FRACTION cause Chapter CIAF CIGN1 Club of Rome coefficient computer model crowding ratio curve death rate normal decline DRFM dynamic ECIR effect effective-capital-investment ratio equations equilibrium exponential growth food production food supply FPMT FRACTION/YEAR in-agriculture fraction increase industrialization INTERPOLATION investment ratio limit LOGICAL FUNCTION material standard mental models mode MULTIPLIER DIMENSIONLESS natural-resource Natural-resource-usage rate negative loop NREM NREMT NRUN1 pollution absorption pollution crisis POLLUTION UNITS pollution-absorption POLN1 population and capital population density PRESENT ORIGINAL pressures ratio CIR result rise Section sector shortage social systems SQUARE KILOMETERS standard of living structure system levels TABHL TABLE LOOK tion units per person UNITS/PERSON/YEAR UNITS/YEAR usage rate variable world model world population world system וד