Note 3: OGNA Review Report Summary

1.1 Opinion Research Services (ORS) was asked by Cherwell Development Watch Alliance to review the methodology, analysis and conclusions of Oxfordshire Growth Needs Assessment 2021 (referred to from here on as the “OGNA” and written by “the consultants”), and in particular its three alternative housing requirements.


1.2 Each of the three housing requirements is derived in a different way.


(1) The “Adjusted” Standard Method uses a questionable methodology where the consultants have created their own demographic projections;

(2) ‘Business as Usual’ is an employment projection based on a period of post 2008 recession high growth, and;

(3) Transformational is an economic trajectory based on an update of the Local Industrial Strategy’s aspirational ‘go for growth’ scenario.


Demographic (i.e. Population) Projections

1.3 The OGNA substantially increases the projected future population of both Oxford and the County compared to the Office for National Statistics 2018 based population projections. The OGNA does this by using what it calls as an “adjusted baseline population projection”. But this projection ignores improvements to population forecasts made by the Office for National Statistics (ONS) in recent years.


1.4 The Office for National Statistics has reduced the official population estimates for Oxford City for 2016 by 6,000 persons, but the OGNA adds almost all of this reduction back into the population of the City.


1.5 The OGNA suggests that the 2050 population of Oxfordshire will be over 10% higher for the County and 35% higher for Oxford when compared with the 2018 based ONS projections. The distribution of the change within the other Districts is uneven with much more of it being in South Oxfordshire and Cherwell.


1.6 The NHS Patient Register is well known to over-estimate populations in student towns like Oxford. However, the consultants use data from this register in their adjustments in a way that we consider to be unprecedented, arbitrary and unjustified.


1.7 The OGNA “Adjusted” Standard Method is very different from, and does not represent, the Standard Method. Its use is unjustified and is contrary to Government guidance.


Employment Projections

1.8 The OGNA explores three main scenarios for Oxfordshire’s future economic growth. The first is based on the number of jobs that would be supported by the housing growth derived from the consultant’s ‘Adjusted’ Standard Method. The other two scenarios are derived in completely different ways and can best be described as being a high jobs growth scenario, and a very high jobs growth scenario


1.9 The OGNA fails to explain that this modelling approach is unconventional and that each of the three scenarios is derived on a different basis. A conventional modelling approach would use a single model to give a central trajectory together with high or low variants based on conservative or more optimistic assumptions. Cambridge Econometrics regularly produce a central trajectory for all local authorities in England and this can be purchased from them, but does not appear to have been included in the OGNA. We would have proposed a more prudent approach and the inclusion of Cambridge Econometrics central projection.


1.10 Very little information is given about the assumptions or source data underlying the jobs growth scenarios and source data references are inadequate eg “ONS, Cambridge Econometrics”. This makes it virtually impossible to understand in any detail how the trajectories have been constructed.


1.11 None of the scenarios appear to be based on trends of growth that have actually been achieved over a long-time period. A central scenario should have been produced as a benchmark for comparison.


1.12 The high growth scenario, described as ‘Business as Usual’, assumes that “robust growth” since the 2008-09 recession will have a strong influence on the projected employment growth until 2050. This is the only modelled trajectory, but in our opinion it significantly over-estimates likely future employment. This has important consequences because the employment projections are used to estimate the number of dwellings that are needed.


1.13 The ‘very high’ Local Industrial Strategy (LIS) transformational scenario is based on aspirational growth rather than an economic projection.


1.14 Both the ‘Business as Usual’ and Transformational scenarios would imply a very large growth in the population of Oxfordshire and this would have wide implications outside of the area i.e. they would require either lower jobs growth elsewhere in the country or more workers nationally overall.


1.15 The three reported employment scenarios have not sufficiently considered the impact of the pandemic, both on long-term job creation and also on the growing trend for working from home. In our opinion this is a serious omission which means that the number of dwellings required is over-stated.


Affordable Housing Need

1.16 In the OGNA, and In line with national guidance, two different types of affordable housing need are estimated.

(1) those who cannot afford to meet their housing costs in the market and

(2) those who can afford to pay their own rents, but who wish to buy and cannot afford to do so.


1.17 We consider that the first group is substantially overestimated because the consultant’s model assumes that, once counted, the only way for households to have their needs addressed is for them to move to affordable housing. There is no allowance for households leaving the area or seeing their household circumstances change for the better. This would still leave a very significant affordable housing need in Oxfordshire, but not as high as is shown in the OGNA.


1.18 The OGNA calculates a figure for households who can afford to rent but not buy. It is unclear how these numbers have been derived, but we believe this is a very large overstatement of need and includes substantial double counting. As such this figure is completely implausible.


Overall Housing Need

1.19 None of the three alternative scenarios for future housing requirements is based on long term economic growth trends that incorporate the likelihood of periodic economic slowdowns or shocks, for example, Brexit, Covid and the current war in Europe. A conventional approach would have included a central economic growth projection.

1.20 Based on updated Office for National Statistics projections for Oxford City we consider that there may be exceptional circumstances in Oxford City (but not in the other Districts) for adopting a housing need figure substantially lower than that given by the Standard Method (as currently formulated). The OGNA should have considered this.


1.21 We consider that the OGNA’s ‘Business as Usual’ economic scenario does not represent business as usual. Instead it represents unusually high growth and results in a housing requirement which also represents a high growth variant.


1.22 The OGNA’s ‘LIS transformational growth’ scenario represents a very high rate of sustained growth only likely to come about as part of national policy-driven redistribution of resources towards the region. The Oxford-Cambridge Arc initiative might have supported a transformational growth scenario but now appears to no longer form part of central Government Policy. It would also appear to be contrary to the Government’s emphasis on a ‘levelling up’ strategy which would direct resources elsewhere in the country.


1.23 The unjustified use of adjustments made to official projections and the Standard Method together with the lack of a conventional central economic forecast call into question the soundness of this document as supporting evidence for the development of the Oxfordshire Plan.