||It is well known that urban expansion is constrained in the UK by Green Belts around the major cities and by other policies. This policy of constraint came into existence after World War Two. The primary driving force at that time was a desire to preserve agricultural land which was perceived to be vital to the nation after the submarine blockade of the war years. This perceived need for agricultural production meant, firstly, that farming was left uncontrolled by the 1947 Planning Act, and, secondly, that it was heavily subsidised, subsidies which continued after the UK joined the EU in the seventies.Things changed around 1980, however. Firstly it was perceived that the drive for increased agricultural production was leading to the loss of some perceived benefits of the countryside as fields were enlarged, hedges removed, ponds drained, etc, and, secondly, that the use of pesticides and herbicides to increase production was leading to a loss of wildlife. Complaints about agricultural surpluses - butter mountains, milk lakes, etc, which led to land being set aside to reduce production meant that there seemed to be no reason to protect agricultural land.The reasons for the policy of constraint changed, however, but not the policy. The perceived need now was to protect the "beauty, peace, and wildlife" of the countryside.The policy continued to be supported because the British population believes various myths - that half or less of England is rural (not the ninety per cent of reality), or that the UK uses its urban land wastefully (actually it's more efficient than almost all other west European countries).The policies are also supported by the wealthy and powerful. Anyone walking in the London Green Belt will find that the land is mostly used, not for agriculture, but for golf courses and for stabling the horses of the rich.The economic consequences of the policy did not change, of course. These are that land and house prices are high and rising, the latter doubling in real terms every twenty five years, but this too is seen as a benefit by the older population who are home owners.But now the young, excluded from buying homes by the current economic crisis, are taking an active interest. Changes in policy appear to be possible and may take place.We wait with interest.