BMO: China trade keeps on humming....While supply factors are no doubt playing a role in the commodity price surge, underlying demand growth must simply be hanging in there for prices to remain so well-supported across the board. GDP growth in each of the U.S., Europe and Japan was in the mild 2%-to-2.5% y/y range in Q4, and looks to be slowing markedly in each region so far in 2008. That leaves the developing world, or the other half of the global economy, to pick up the slack. One hint that growth is still chugging along in emerging markets is that China reported still-strong gains in both exports (27%) and imports (28%) in January from a year ago. The developing world can not fully decouple from the U.S. economy, but it appears it can ride in a different box car.