The committee has faced criticism from some deputies for basing its proposals on outdated data. Deputy Rob Curgenven pointed out that the current modelling predates the results of the latest Household Expenditure Survey.
P&R said that was being addressed.
‘The intention is to update the modelling with the updated household expenditure data,’ the committee said.
‘This is a significant piece of work that has been carried out in recent weeks, but the committee will release the output from it prior to the continuation of the tax reform debate.’
The committee also dismissed suggestions that its tax package would dampen demand in the local economy, saying consultants Deloitte had concluded the proposals, taken as a whole, could modestly stimulate spending.
‘Their conclusion was that a GST would reduce consumption in the short term, and that a reduction in direct taxes might increase consumption,’ the committee said. ‘Their analysis suggested that applied in combination this could result in a slight increase in consumption, particularly if reductions in direct taxation are focused on those at the lower end of the income scale.’
P&R also revealed that its modelling is built on personal data held on every islander through the rolling electronic census, and confirmed it would not release the modelling itself, in order to protect individuals and families from being identified.
‘While all data sets are pseudonymised before inclusion in the model, the extent of the data on individuals and its treatment, which condenses individual data into households, means that it is possible to identify individuals and households from the data set, particularly where circumstances are unusual,’ the committee said.
Access to the modelling is restricted to a small number of people sworn in as census officers, including five civil servants who worked on it and staff at Dorey Financial Modelling, the firm retained to check P&R’s work.
‘Dorey Financial Modelling work with rolling electronic census data to support the production of demographic and economic forecasts,’ the committee said.
‘Their officers are sworn in as census officers and must comply with the same restrictions on the processing and management of that data as States of Guernsey officers.’
No politicians, including members of P&R, are sworn in as census officers, so none has seen the underlying data, though all have been given full access to the outcomes of the modelling.