A poll for The Telegraph by Redfield & Wilton Strategies earlier this month found that the economy is the most important issue for the largest group of voters in all seven swing states.
About 70 per cent of voters in the battleground states said that the cost of living would be “extremely important” in determining their vote.
The largest group of voters in all seven states, including those where Ms Harris is ahead overall, said they trusted Trump more on the economy.
In a press conference in New Jersey on Thursday, Trump criticised the Biden administration’s record on economic policy, including the president’s industrial policy, which has been nicknamed “Bidenomics”.
“Kamala Harris is a radical California liberal who broke the economy, broke the border and broke the world, frankly,” Trump said.
Earlier this month, Trump accused Ms Harris of stealing one of his flagship policies, after she announced she supported ending taxes on tips received by hospitality workers.
She announced support for the policy on Saturday, months after Trump said he would make the ban a priority of his second administration if he wins back power in November.
‘Bidenomics’
Ms Harris’s other economic policy plans include a continuation of “Bidenomics”, which looks set to be rebranded after Mr Biden dropped out of the presidential race last month.
Mr Biden said on Thursday night: “It doesn’t matter what the hell you call it, the economy is going to continue. With all the legislation we passed, it’s working.”
Asked about Trump’s plan to “make America affordable again”, he replied: “Well, he ought to get a job.”
Ms Harris has also proposed a new house building programme, which she says would lead to three million homes being constructed within four years to “end the housing supply shortage”.
Campaign officials said she would also give each family with a newborn child $6,000 (£4,650) in tax credits within the first year of its life.
Ms Harris was set to deliver the announcements to a crowd of supporters in Raleigh, North Carolina, on Friday evening.