Cost increases have led to reductions in the planned track; for instance, the link between HS1 and HS2 was later dropped on cost grounds. In April 2016 Sir Jeremy Heywood, a top UK civil servant, was reviewing the HS2 project to trim costs and gauge whether the project could be kept within budget. The cost of HS2 is around 25 per cent higher than the international average, which was blamed on the higher population density and cost of land in a report by PwC. The costs are also higher because the line will run directly into city centres instead of joining existing networks on the outskirts. By 2019, Oakervee estimated that the projected cost, in 2019 prices, had increased to £80.7 billion to £88.7 billion—the budget envelope in 2019 prices is £62.4 billion—and the benefit–cost ratio had dropped to between 1.3 and 1.5. Lord Berkeley, the deputy chair of the Oakervee Review, dissented from Oakervee's findings and contended that the cost of the project could now be as high as £170 billion. As of 2020, the budget envelope set out by the DfT is £98 billion.