Federal Reserve Chair Jerome Powell used the word "uncertainty" 16 times in his press conference today. We sympathize. At the outset, it's impossible to know what tariffs will be imposed by the US on April 2., on which countries, and for how long. When the specifics are revealed, it will still be difficult to forecast their impact on economic growth and inflation in the US and around the world. Another known unknown is the response of America's trading partners to reciprocal tariffs. Will they lead to negotiated reciprocal reductions in tariffs or to escalating retaliatory tariffs?