Tackling planning delays and housing under-supply across England: Can inter-municipal cooperation between local planning authorities help?

There are significant and stubborn backlogs in the English planning system. Government statistics, which are known to under-estimate planning delays (Ball, 2011), show that less than half of development applications sent to local authorities in 2021 were determined on time (RTPI, 2022a), down from nearly 80% in the mid-2000s. A recent survey of architectural firms found that 47% had experienced delays of greater than six months; and 22% had cancelled projects as a result (RIBA, 2023). Just 40% of councils have up-to-date "Local Plans" for meeting future housing needs (Levelling Up Committee, 2023). And enforcement activity has declined by 30% since 2008 (RTPI, 2022a), risking more unregulated development that breaches quality or environmental standards.

There is a notable spatial dimension to these problems. Being a locally-run and "discretionary" system, English planning has long been accused of being a postcode lottery (BUILD Magazine, 2019; Local Architects Direct, 2021). But the last decade has seen new inter-regional disparities emerge, reflecting "the uneven geography of local government austerity" (Gray & Barford, 2018). Overall expenditure on planning declined by 43% between 2009 and 2021; but the reduction was 62% in the North East, where local fiscal capacity could not offset central cuts (RTPI, 2022a). Application processing speeds dropped by, on average, 31% between 2013-2022, but the North East and West Midlands saw far greater declines. And while most councils now struggle to recruit and retain graduate planning officers, the problem is most acute in rural authorities (LGA, 2022; RTPI, 2022b).

Planning delays contribute to multiple social and economic ills. Land-use regulations restrict housing supply (Gyourko & Molloy, 2015; Dawkins, forthcoming). Even if fully-justified to serve other policy objectives, this slows economic growth (e.g., by restricting the talent pool available for business expansion), inhibits productivity (through long commuting times), and creates or exacerbates spatial, demographic and inter-generational inequalities (Szumilo, 2019). And the problem is not only regulatory design, but also how swiftly and predictably regulations are implemented (Ball, et al., 2009; Ball, 2011). As the Home Builders Federation recently argued, "Chronic under-resourcing and under-staffing in local planning authorities is leading to discrepancies, administrative errors and delays for developers" (see Built Environment Committee, 2022).

Given the likely continuation of austerity, councils are looking to administrative innovation to reverse the decline in planning performance. Since 2008, at least 17 have merged their planning teams with one or more neighbour to provide a "shared service" across several authorities. This de-facto regionalization should generate scale economies, critical mass in specialist planning roles, and an enhanced employment "offer" - improving organizational performance and reducing delays. Further, to manage regional spillovers more strategically and provide more consistent regulations for developers, 32 councils have collaborated on "Joint" Local Plans, again aiming to boost housebuilding.

Using postcode-level planning data, we shall evaluate the separate and combined effects of these two "re-scaling" interventions - one organizational, the other policy-focused. Our key question is: does either form of "inter-municipal cooperation" reduce planning delays and increase housing supply? Our spatial regression discontinuity design enables robust comparison of geographically-proximate planning applications that, falling on either side of an administrative boundary, are differently processed by either "treated" (i.e., collaborating) or "controlled" councils. The results will provide timely evidence on whether this type of administrative innovation should be extended further, and on how local public services affect economic outcomes.