The U.S. Treasury has reported customs duty income of $6.45 billion in December, up by 7.6% compared to a year earlier. That came despite a 5.7% dip in merchandise imports resulting from the drag on demand from tariffs on imports from China. The ratio of duties to imports of 3.2% in December was below the peak level of 3.7% seen inOctober due to the effect of demand deflection. Looking ahead, the phase 1 U.S.-China trade deal will only make a small dent in duty income – effectively a tax paid by American importers – of $620 million out of the $4.09 billion resulting from section 301 duti...