We propose an adaptation of Hartwick's investment rule to models with population growth and show that following Hartwick's rule is equivalent to a time-invariant real per capita net national product. In the so-called DHSS model of capital accumulation and resource depletion the proposed...

We set out dollar-valued net national product for an economy with a wasting essential stock (oil deposit). We take up 'maintaining capital intact' and locally unchanging consumption. The percentage change in 'net investment' or 'genuine savings,' relative to the market rate of interest, denotes...