So they should just say that they think the value of behavioural changes is 500 mill and leave it at that.
What they shouldn't say is the Labor policy won't make the money they claim. They also shouldn't put a header "Impact on Govternment Revenue Estimates" or 'Effect of ....on Oppositions Costings' or "However, as this policy will incentivise people to change their asset allocations, the change may not raise as much revenue as anticipated. As the change will likely see a shift away from Australian equities, there may also be unintended consequences for the Australian share market."
