however national laws stipulate that rents can be raised in designated monument areas which then impedes upon the desire for mixed neighbourhoods some academics have declared the end of the planning doctrine alongside a diminished role for the dutch social welfare state in particular it has been argued that the green heart as a national policy concept was a cornerstone of the planning doctrine and that its demise thus marks the end of this approach faludi faludi and van der valk roodbolmekkes van der valk altes in support of this argument between and the population growth rate in the green heart was which was higher than the national average over that time at indicating that the area does indeed face development pressure needham