I think we'd benefit from organizing our thoughts, and talking about specific scenarios with labels.
Scenarios:
1. Widespread/high tariffs as announced
1.a. Stocks go up despite tariffs
1.b. Stocks go down
2. No tariffs or very short/small/targeted tariffs
2.a. Stocks go up despite tariffs
2.b. Stocks go down
What's not really up for debate among economists or informed people is the consensus that tariffs are a tax on consumption that create deadweight losses and discourage some consumption of the things taxed at the margin. Decades of experience have taught us that tariffs reduce trade, GDP, and living standards.
For example, G.W. Bush's
steel tariffs between March 5, 2002 and December 4, 2003 coincided with a -7.59% move in the S&P500's price.
That said, all 4 outcomes are still possible. Assign probabilities to them if you like. I'd suggest scenarios 2.b. and 2.a. occurred during Trump 1.0, as the damage of
targeted tariffs between 2018 and 2019 was absorbed by fast economic growth elsewhere. However,
rising CPI during that time briefly supported the Fed's ambitions to raise rates above 2%.
S&P500 total returns during tariff years of 2018-2019:
2018: -4.38%
2019: +31.49%
Did Trump's trade war cause the negative return in 2018? Did partial relief of tariffs in exchange for trade deals in mid-May 2019, or hope of tariff relief starting in January 2019, cause the sharp rebound in 2019? These questions are the questions up for debate.
I do not think it is wise to assign a 0% chance to any of the four outcomes, but I will agree that the addition of the tariffs factor increases the odds of a negative stock return.