Anti-avoidance costings: an evaluation

Since 2010 the government has announced a large number of policy measures aimed at reducing the level of tax avoidance and evasion and to enhance the compliance performance of Her Majesty’s Revenue & Customs. These measures have been one of the Government’s preferred sources of revenue-raising in recent Budgets and Autumn Statements and costing these types of measures is typically subject to considerable uncertainty. This paper reports on the performance of 59 measures announced and implemented between 2010 and 2015. We find that the yield from the majority of measures is reasonably close to the original estimate, but there are more under-performing measures than over-performing ones. We also find that costings have, on average, underestimated the amount of time that it would take before a measure becomes fully effective.