It would have been helpful, to author and reader alike, if our treatment of the subject could have been placed from the outset in some recognisable wider context, within which our particular approach could be pursued. But this is not so. The elements in the subject which are expressed in our title are in themselves diffuse and not clear cut, while the approach to and understanding of them have changed vastly. We therefore need to start with an Introduction which places them in some perspective from their evolution over this century. From this it will be apparent that the wider context touches upon great variety in our lives. This very variety means that the brief Introduction can be only sketchy. A guide to its further exploration is given in the footnotes and Bibliography.

The scene for our detailed study of economics in conservation is broadly sketched out in Part I. From the various meanings of the term urban (1.1) we choose the most familiar: the parts of the earth's surface which are built up as opposed to rural and open. Within this we see not just bricks and mortar but also the areas left to nature, the people themselves and their mobile goods as well as the immobile bricks and mortar (1.4). But while this concept of the urban area has remained, its size, distribution and functioning has changed violently over the century (through change in transportation, communication, distribution of income and wealth, etc., leading to widespread and damaging obsolescence) (1.6). And with the change has grown the awareness of the need for conservation (1.8) and the role of management and planning in achieving it (Chapters 2 and 3).