NZIER said we'd be looking at huge tariffs on our imports, the end of trade deals like NAFTA and TPP and highly volatile markets.
"Even a slight slowing in the US economy, which most economists think Trump's policies will result it, will see them demanding less of what we sell. So I think New Zealand's firms start planning for a scenario where Trump is present," Mr Ballingall said.
Travel Money New Zealand is warning holidaymakers, particularly those heading to the United States, to get their currency sorted before they head away.
Manager Daniel Jackson said it's likely the election next week will rock the markets - but it's not clear which way it'll go.
"The US dollar against the NZ dollar, we're pretty strong at the moment so for those people that want to avoid that chaos, if you will, jumping in now may be the best bet.
"When the Britons voted to leave the EU it had a huge impact on the value of the Pound, and that saw queues out the door in our shops as the Pound devalued."