Exercise 18.25. Consider the model of appropriate technology in subsection 18.4.3. (1) Suppose that now research firms can sell their machines to all producers in the world, including those in the South and can charge the same markup. Derive the steady-state equilibrium under these conditions. (2) Comparing your answer in part 1 to the analysis in the text, derive the implications of intellectual property rights enforcement in the South on equilibrium technologies? What are the implications on income per capita differences between the North and the South? (3) In view of your answer to 1 and 2 above, could it be the case that Southern economies prefer lack of intellectual property rights enforcement to full intellectual property rights enforcement? [Hint: distinguish between a world in which there is a single Southern country versus one in which there are many].