In its latest Economic Overview Westpac economists provide a guide to this year's election for financial markets.
It says Labour and the Greens propose broadening the tax base and introducing a CGT, which would be levied at 15%, payable on realisation, but the family home would be exempt.
Labour also proposes to ring-fence losses for residential landlords, meaning losses can't be offset against other income for tax purposes.
"We support the introduction of a CGT, because it will help right the current misallocation of resources to land-based economic activities, and would lift the rate of home ownership."
"By broadening the tax base, a CGT may allow other distorting taxes to be reduced in the future."
Westpac says CGT plus ring-fencing losses would affect house prices by discouraging investors.
"We calculate that a 15% CGT would reduce the value to an investor of a given property by 23%, if rents remained unchanged. Even if we assume a 10% lift in rents, the loss in net present value of the house to the landlord is still 15%."
The ecnomists also say that removing the tax-free status of capital would also impact farm prices.
They also say that if Labour were to led a broad coalition of the centre/left in the next government the market implications would be substantial. Overall there would be a downturn in economic activity and that would mean fewer Official Cash Rate hikes over 2015 and 2016. If National led the next government then it would be business-as-usual and the OCR would continue to gradually rise.
