How much would Trump's '$5,000 to every adult' promise cost US economy?

US President Donald Trump proposed $5,000 for every American adult if Republicans retain control of both chambers of Congress in November midterms. This would cost around $1.35 trillion or around 3% of the US' GDP for approximately 270 million adults, Reuters reported. The payout, called "Trump dividend", raised ethical concerns as it comes amid Trump's falling popularity ratings.