g An economy’s potential output is equal to $140 billion, and its current output is equal to $125 billion. If the marginal propensity to consume has a value of 0.4, then the government should increase spending by billion to return the economy to the long-run equilibrium.

When cell phones were first entering the market, they were relatively large and reception was undependable. all cell phones were essentially the same. but as the technology developed, many competitors entered, introducing features unique to their phones. today, cell phones are only a small fraction of the size and weight of their predecessors. consumers can buy cell phones with color screens, cameras, internet access, daily planners, or voice activation (and any combination of these features). the history of the cell phone demonstrates what marketing trend?