The Treasury also said the government may want to look at the corporate tax rate, which at 28 per cent is above the OECD median, but said it could look at ways to reduce effective tax rates on business investment such as modifying depreciation rules.
"Significant misalignment between personal and company tax rates could put pressure on the integrity of the revenue base," it said.
The agency said the government has signalled significant monetary policy priorities, including reviewing the Reserve Bank Act to broaden the central bank's objectives.
The agency suggested Robertson use the signing of the policy targets agreement with the next governor of the Reserve Bank, which he will do by March next year, as "an early chance to reconsider how monetary policy objectives are specified" and said it may be a good time to consider broader issues about governance and monetary and financial stability frameworks in the act.
The Treasury recommended a review of the statutory framework for financial stability policy to ensure the country can respond to emerging financial risks.
"The growth in scope of prudential policy over recent years makes it timely to stand back and consider whether the statutory framework is fit for purpose, particularly given there are aspects of our approach that differ from international norms," it said.
The Treasury said progress towards Labour's budget responsibility rules can be achieved through greater increases in operating and capital expenditure than in previous budgets, as the government indicated in its pre-election fiscal plan.
The agency is currently reviewing aspects of the fiscal management approach, which gives fixed baselines to government agencies with no automatic adjustments for inflation and other pressures in each budget, meaning spending comes through the budget process and allowances. Robertson must decide whether to keep this approach.
The government has said it plans to reinstate contributions to the New Zealand Superannuation Fund in the current financial year, and Treasury recommended establishing a review of the fund's contribution and withdrawal formula "to ensure that settings support the objectives of the NZSF, including intergenerational fairness."