However, while many were willing to accept such a tax, it would be the exemptions and the design detail that would determine its success, he said.
Labour finance spokesman David Parker reiterated last week a capital gains tax would help a Labour-led government run surpluses and pay down debt.
Mr Turner said it would be great to get the capital gains tax debate to occur on a rational and well-reasoned basis.
''There are a number of myths regarding capital gains tax that need to be dispelled.
''The suggestion that a capital gains tax will avoid a future housing bubble is simply incorrect. One only has to look at Australia to see other factors are much more significant than the impact of capital gains tax.''
The argument New Zealand should have a capital gains tax because others in the OECD did was weak justification, he said.
New Zealand should be looking to learn from other countries and do what was best for New Zealand, rather than simply replicating what others did.
A capital gains tax had some benefits but there were also disadvantages, such as providing an incentive for people to hold assets that they would otherwise sell to free up cash to invest in more productive sectors of the economy, Mr Turner said.
''The locking-in effect of a capital gains tax can be quite distortionary.''
In addition, many countries that had exempted the private home from the tax had found that the exemption, rather than encouraging investment in the productive sector, encouraged people to buy grander and more expensive private homes.
The ''mansion effect'' had been seen in other countries and was likely to be seen in New Zealand if the tax was introduced, he said.
A well-recognised philosophy of a good tax system was broad-based and low rate. While a capital gains tax broadened the base, Labour's suggestion of increasing personal tax rates at the same time - bringing in a number of exemptions - called into question whether Labour had the design issues correct.
''Labour does talk about future income tax reductions which might bring them within a broad-based design philosophy but this is only a possibility.''
Implementation suggested a capital gains tax being forward-looking and applying only to gains after implementation, Mr Turner said. That meant the need to value property at the date of introduction, which undoubtedly would be a field day for valuers.
The suggestion of exemptions for the family home, personal assets, collectables, small business assets sold for retirement, and payouts from retirement savings all diminished the broad application of the tax and called its appropriateness into question.
''While many, including people within IRD and the Treasury, favour a capital gains tax, it is a broad capital gains tax without exceptions which is generally supported.''
Under the Labour policy, capital gains would be subject to a flat 15% taxation with capital losses able to be carried forward and offset against future gains.
There would be room for debate whether some amounts were simply income to a person and taxed at, say, 36% or were capital gains and taxed at only 15%, he said.
Labour suggested assets passed on through death would be subject to rollover relief and a capital gains tax would not be payable until the asset was eventually sold.
That created a ''very real prospect'' assets would be passed from generation to generation in wealthy families and never be subject to the tax.
An expert panel was proposed to work through the detail of the design of Labour's capital gain tax. However, experience in foreign countries suggested valuers, accountants and lawyers were all in line to benefit from the introduction of such a tax, Mr Turner said.
