Anticipate 200k deaths by September, just before the second wave. The economist might know his stuff, but he's not an epidemiologist.
There is no indication that warmer weather will slow down this virus. There is no cure. It will do what it will do. Mitigation measures will be partially successful, but the infections won't stop.
Trumpy-boy will try to keep the economy rolling, but the infections and deaths will take their toll. Consumers will stop consuming because there is no cure for the virus and people will continue to die. The economy relies on consumption. It's driven by the purchase of goods and services. High unemployment means that people have no money to spend, and for those who do have disposable incomes, the virus will infect people who circulate. So the act of spending is dangerous.
The US and most of the world has not seen this kind of thing in over a hundred years. We don't want to alter our lives to the extent that we will stabilize around the live virus and we don't know how to establish new norms. Our normal activity, for decades long, must cease until a vaccine is developed and administered to vast numbers of people. That will take YEARS.
Biden can win merely by telling the truth. People want to hear the truth. They are done with lies and con games, and their disgust will grow. Sure, Trump will cheat and he'll lie, but he's no longer an unknown quantity. Cheating and lying will no longer be a surprise. We EXPECT Trump to try to win the election by cheating. Everyone's antennae are up. The press will be hypersensitive to voter/election fraud. Trump won't be able to pull of a fraudulent election because everyone will know about it in advance.