ABSTRACT
It is more difficult to be specific about many of the other coefficients. The household activity rate has probably decreased over time through younger members of families staying in education longer and more women working as housewives. This may now begin to increase again wi th an increasing tendency for women to work. The transport deterrence parameters have consistently decreased over time: travel has become easier. But again this may cease to be the case in the light of successive oil crises. Typically, the costs of supplying a unit of urban structure - the coefficients qf and k] - have probably decreased over time, at least in real terms while the cost of land r i , will have increased due to its increased productivity.
