How does the multiplier-accelerator model magnify changes in demand? How does the permanent income hypothesis affect the multiplier model? Why? Traffic engineer Hans Monderman has shown that traffic...

How does the multiplier-accelerator model magnify changes in demand? How does the permanent income hypothesis affect the multiplier model? Why? Traffic engineer Hans Monderman has shown that traffic flows can be made safer and flow better if the number of road signs is reduced and, in many types of intersections, eliminated altogether. What relevance do his insights about traffic flows have for macroeconomic policy?