期刊名称：Departmental Discussion Papers / University of Glasgow, Department of Economics
出版年度：2009
卷号：1
出版社：University of Glasgow, Department of Economics
摘要：The Ramsey model of economic growth is revisited from the point of
view of viability compared to optimality. A viable state is a state from
which there exists at least one trajectory in capital, consumption, and reproduction
that remains in the set of constraints of minimal consumption
and positive wealth. There exists a largest set of viable states, including all
others, called the viability kernel. This concept is an interesting addition
to those of equilibria and optimal paths. Viability is first presented with
a constraint of minimal consumption, then with an additional criterion of
economic sustainability in the sense of the Brundtland commission, which
amounts to requiring a non-decreasing social welfare. The comparison of
viability kernels with or without sustainability shows how much consumption
should be reduced and when. One strong mathematical result is that
the viable-optimal solution in the sense of inter-temporal consumption is
obtained on the viability boundary of an auxiliary system. Varying preference,
technological, and demographic parameters randomly over simulated
viability kernels with and without the Brundtland criterion help identify
the determinants of the non-emptiness of the viability kernel and of its
volume: technological progress works against population growth to favor
the possibility for a given state of being viable or viable-sustainable.
关键词：Viability theory – Optimization—Sustainability—Ramsey model
