World Dynamics

1970 conditions accumulation agricultural land assumed assumptions behavior birth rate normal birth-control program BRFM BRMM 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 ratio food supply FPMT FRACTION/YEAR in-agriculture fraction increase industrialization INTERPOLATION limit LOGICAL FUNCTION material standard mental models MULTIPLIER DIMENSIONLESS natural resources natural-resource Natural-resource-usage rate negative loop NR=N NREM NREMT NRUN1 POLN1 POLAT POLCM pollution absorption pollution crisis pollution-absorption population and capital population density PRESENT ORIGINAL pressures ratio CIR RATIO DIMENSIONLESS result rise Section sector shortage social systems SQUARE KILOMETERS standard of living system levels TABHL TABLE LOOK TIME.K tion units per person UNITS/PERSON/YEAR UNITS/YEAR usage rate variable world model world population world system