The reduction in world poverty from 1990 to 2014 was due almost entirely to the decrease in poverty in

The substitution effect indicates that a profit-seeking firm will use:

A. more of an input whose price has fallen and less of other inputs in producing a given output. B. more of all inputs if production costs fall. C. more of those inputs whose marginal productivity is the greatest. D. less of an input whose price has fallen and more of other inputs in producing a given output.

Cite three important reasons why nations trade.

What will be an ideal response?