To be fair to the DWP, ex ante assessment of the impacts of policy change is difficult. Especially when the impacts rely upon behavioural effects that are unknown and unknowable in advance. So when it modelled the savings from the implementation of the so-called bedroom tax it was always going to represent a broad estimate. The DWP quite rightly conducted sensitivity analysis to see how robust its conclusions were to different assumptions on key variables.
However, once the policy is in place real data will begin to emerge and ex ante assessments can be recalibrated. That is what Rebecca Tunstall of the Centre for Housing Research at York has attempted. Her report, published yesterday, has generated considerable political and media interest.
The brief report is well worth reading, for several reasons. [Read more...]