Abstract The Metropolitan Green Belt (MGB) was established in the 1930s and has expanded enormously since. Accompanying polices, including New Towns, have since been abandoned, leaving the MGB as an ‘orphaned’ policy which constrains land supply. Prioritising the reuse of Brownfield land and densification are now the counter to land constraint. However, it is argued that these are not sufficient to meet the housing crisis in London and the Wider South East. Moreover, academics have pointed out for decades that strong land constraint has led to chronic housing problems, including poor internal space standards and the high cost of housing in the ‘mega-region’. However, despite decades of academic discussion concerning the chronic housing problems it contributes to, and the more immediate crisis, the MGB remains a bluntly applied planning tool and carries with it no serious political discussion of reform. Piecemeal change has taken and still takes place, but this has led to a series of battles that have not achieved the core task of signalling the intention to make a sustained and substantial change to policies of land constraint. In order to chart a possible path to reform the starting point is to approach the MGB as an institution, and this includes tracing the significance of how it developed historically, and in particular the confusion over the full extent of its purposes and, thus, the real range of its benefits. A second strand is a consideration of the different reasons why people commit to institutions, and how this differentially impacts the way in which they respond and/or seek to drive institutional change. Using these insights, existing proposals for change are critiqued and then an alternative is proposed that seeks to respond to the ‘rational’ and ‘normative’ drivers of support for the MGB.

中文翻译：

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大都会绿化带，改变一个机构

摘要 大都会绿化带 (MGB) 成立于 1930 年代，此后得到了极大的扩展。包括新市镇在内的配套政策此后已被放弃，使 MGB 成为限制土地供应的“孤儿”政策。优先再利用棕地土地和致密化现在是对土地限制的反击。然而，有人认为这些不足以应对伦敦和更广泛的东南部的住房危机。此外，几十年来，学者们一直指出，强大的土地限制导致了长期的住房问题，包括内部空间标准差和“特大城市”的住房成本高昂。然而，尽管数十年来学术界讨论了它造成的长期住房问题，以及更紧迫的危机，MGB 仍然是一个直接应用的规划工具，并没有对改革进行严肃的政治讨论。零星的改变已经发生，而且还在发生，但这导致了一系列的战斗，没有达到核心任务，即表明要对土地约束政策进行持续实质性改变的意图。为了绘制一条可能的改革路径，起点是将 MGB 作为一个机构来处理，这包括追溯其历史发展的重要性，特别是对其目的的全部范围的混淆，因此，它的好处的真正范围。第二个方面是考虑人们对制度做出承诺的不同原因，以及这如何对他们做出反应和/或寻求推动制度变革的方式产生不同的影响。