The temporary stamp duty holiday announced by Rishi Sunak could push up house prices, the Institute for Fiscal Studies (IFS) said.
More, it's unlikely to help anyone new buy a home or even see more property bought and sold overall - instead, it will simply see people buy sooner and spend more to compensate for the tax they save.
IFS deputy director Helen Miller said: "Although it's buyers who are formally required to hand over stamp duty, the effect of stamp duty can be passed through to sellers.
"So when there is a tax break that can lead to the price of houses going up."
The move was likely to boost activity in the housing market, although pent-up demand generated during the lockdown may mean that a stimulus was not necessarily needed at this point and could have been more effective at a later date.
Sean Randall, partner at tax firm Blick Rothenberg was blunter.
"The Chancellor has put a mask on the face of the housing market. The real story is what will the face look like when it is lifted," he said.
“Past experience shows us that sellers tend to benefit stamp duty holidays, enjoying on average almost half of the saving.
“Agents will be delighted. The combination of a stamp duty holiday and pressure on non-residents to complete before the 2% surcharge kicks in next April will give those that were contemplating buying this year a real incentive to act.
"Those that are wary of a possible 10% fall in the market, prompted by the deepest global rescission since records began and rising unemployment, are unlikely to change their plans until confidence returns."
There were also concerns it would hurt first-time buyers, as prices rise and they lose their comparative advantage.
Jamie Ward, head of stamp taxes at PwC, said: “Buyers often pay the maximum amount they can afford, both the price for the house and the stamp duty in total. Consequently, buyers not paying a percentage of the property’s value to the government as stamp duty may have larger deposits and a better chance of securing a mortgage."
He added: “First time buyers, who may benefit from a stamp duty exemption for properties below £300,000 and a partial relief on purchases up to £500,000, do appear to lose their current competitive advantage."
