Integrated Environmental and Economic Accounting

With Ecological Interaction

This study first aims to derive a consistent integrated environmental

and economic accounting under

a framework of social intertemporal optimization problem for a nation's

economy. It is observed that

the current value Hamiltonin introduced to solve the problem gives an

environmentally adjusted net

national product. It is also shown that household total expenditure in

the integrated environmental

and economic accounting illustrates an environmentally adjusted gross

national product. An ecosystem

with two species is internalized in the present model with its

properties being theoretically examined.

The Hamiltonian appeared in the ecological dynamics gives a kinetic

energy of the ecosystem defining

a new environmental evaluation index. Since conservation of the

Hamiltonian implies an environmental

protection, a necessary and sufficient condition for the conservation of

the Hamiltonian is considered.

Ecosystem is classified into two types, namely, conservative and

dissipative, depending on its property.

The two types of ecosystem are theoretically compared with each other.

　本研究は一国の経済における社会的動学最適化問題から，整合的な環境・経済統

合勘定を導くことを第１の目的とする。その際，ハミルトニアンが環境調整国民純

生産を与えることが確認される。また環境・経済統合勘定の家計部門総支出は環境

調整国民総生産を与える。本モデルでは２種の生物から構成される生態系が内生化

され，生態系ダイナミクスの特性も併せて検討される。生態系ダイナミクスのハミ

ルトニアンは生態系の運動エネルギーを与え，それ自体が新たな環境指標を定義す

る。そしてハミルトニアンを保存することが，環境保全対策となり，このための必

要十分条件が検討される。生態系はその特性により保存系と散逸系に分類され，そ

れらの比較も行う。