Spiking trade uncertainty is compounding rising debt and sluggish growth problems facing emerging markets and developing countries, but cutting their own tariffs could provide a big boost, said Indermit Gill, the World Bank's chief economist. Gill said global economists were rapidly lowering their growth forecasts for advanced economies and somewhat less so for developing countries, at least for now, in the wake of a tsunami of tariffs announced by U.S. President Donald Trump.