Sustainability from an economic perspective

Introduction
In 1987 the World Commission on Environment and Development tried to resolve the problem that lies in contradictions between environment and economical goals; the result was formed in definition of sustainable development: ‘Sustainable development is development which meets the needs of the present without compromising the ability of future generations to meet their own needs’ (Smith & Rees 1998, p. 15). Since that long time ago 1987, there have been a lot of researches in this field, and three essential aspects of sustainable development have been defined (Kronenberg & Bergier 2012, p. 24). At first, there is economic – a sustainable system must be able to produce goods and services on a permanent basis, to maintain appropriate levels of debt (government as well as external one), and to avoid significant disbalance in different sectors (that can damage agricultural or industrial production). Second one is environmental aspect – a sustainable system must maintain a stable resource base, avoid over-exploitation of renewable resources, and exhausting nonrenewable resources only if adequate substitutes exist. The last aspect is social one - a sustainable system must characterized by fair distribution and opportunity for everybody, provision of social services (like health, education, etc.) on the adequate level, gender equity, and political accountability and participation (Hofkes 1996, p. 342).These three aspects of sustainability make the originally simple definition of economic development more complicated or more precise, in other words.
Sustainability from an economic perspective
Despite on these complications, three principles, outlined above have resonance at a common-sense level. According to viewpoint of neo-classical economic theory, sustainability can be defined in terms of the maximization of