Why have economists in the room?

Good politics makes bad economics and vice versa. The Trump administration's ideas on trade prove it. In today's WSJ, we see that "Trump eyes change in counting U.S. exports that could make trade gap look bigger."

Adam Smith pointed out many years ago "Nothing can be more absurd than the balance of trade." This "balance" (current account deficit) is reported and fretted over regularly. But less noticed is the simple fact that the deficit is necessarily mirrored by an equal and opposite surplus on the capital account.

Currency exchange rates reflect the supply and demand for any and all currencies. Supply and demand for any nation's goods and services as well as supply and demand for any nation's capital goods determine supply and demand for any nation's currency.  At the end of the day, currency values price and prompt all of these trades. 

Put it another way: Americans get to consume more than they produce because the world wants to invest in American capital goods. This also means that American taxpayers (and politicians) can consume more than they produce. Sweet deal all around.

What are the lessons? The world wants to invest in the U.S. Good news. The "trade gap" proves it.

It would be even better if the federal government (politicians) did not reap the benefits. These "investment opportunities" though attractive abroad (for the most part) do little good.  Far better if foreigners used their U.S. dollars to make productive U.S. investments.

Gains form trade are fundamental and beneficial.  Double-entry booking is also fundamental and beneficial.  I understand the politics. But why have economists in the room if they simply parrot the politics?