At first, most households tend to be in an Acquisition State, having both landlines and an increasing number of cell phones. Next, households begin to progress to a Transition State slowly dropping their landlines while retaining their cell phones - hence, the overall consump- tion drop. The final upward slope represents the steady state, in which population growth(and associated cell phone acquisition) is the only factor affecting energy consumption Optimal Telephone Adoption Imagine an emerging nation without phone service but with an economic status roughly similar to the current United States. We now examine two hypothetical scenarios for introducing phone service to this nation Cell phones Only · Landlines Only Because it took Russia roughly 6 years for cell phone penetration to go from 2 percent to 105 percent ITU, we assume a similar timescale for introducing cell phones to our hypothetical nation. Furthermore, a country with the same economic status as the U.s. should be capable of making a similarly quick adoption of either cell phones or landline phones, even though landline phone infrastructure involves the extra complexity of laying cables Cell Phones Only For our cell phone introduction plan, we assume that 0 percent of the population in 2009 has been given cell phones and that 100 percent of the population in 2015 has been given a cell phone. If we interpolate linearly between these two dates, we can derive the number of people that will be given a cell phone in any month during the 6 year period. If we assume that the rate at which cell phones consume energy remains roughly the same between 2009 and 2015 then we have all the information we need to run our simulation The only major change we make to our model is that the Initial State of a household now involves having no phones at all, and the Final State involves each household member owning a Cell Phone Nation=- 1200 The UMAP Journal 30(3)(2009). @Copyright 2009 by COMAP, Inc. All rights reservedAt first, most households tend to be in an Acquisition State, having both landlines and an increasing number of cell phones. Next, households begin to progress to a Transition State, slowly dropping their landlines while retaining their cell phones – hence, the overall consump￾tion drop. The final upward slope represents the steady state, in which population growth (and associated cell phone acquisition) is the only factor affecting energy consumption. Optimal Telephone Adoption Imagine an emerging nation without phone service but with an economic status roughly similar to the current United States. We now examine two hypothetical scenarios for introducing phone service to this nation: • Cell phones Only • Landlines Only Because it took Russia roughly 6 years for cell phone penetration to go from 2 percent to 105 percent [ITU], we assume a similar timescale for introducing cell phones to our hypothetical nation. Furthermore, a country with the same economic status as the U.S. should be capable of making a similarly quick adoption of either cell phones or landline phones, even though landline phone infrastructure involves the extra complexity of laying cables. Cell Phones Only For our cell phone introduction plan, we assume that 0 percent of the population in 2009 has been given cell phones and that 100 percent of the population in 2015 has been given a cell phone. If we interpolate linearly between these two dates, we can derive the number of people that will be given a cell phone in any month during the 6 year period. If we assume that the rate at which cell phones consume energy remains roughly the same between 2009 and 2015, then we have all the information we need to run our simulation. The only major change we make to our model is that the Initial State of a household now involves having no phones at all, and the Final State involves each household member owning a cell phone. 0 200 400 600 800 1000 1200 1400 1600 ’10 ’12 ’14 ’16 ’18 ’20 ’22 ’24 ’26 ’28 ’30 Power Consumption (Megawatts) Time Cell Phone Nation Figure 6. The UMAP Journal 30 (3) (2009). ©Copyright 2009 by COMAP, Inc. All rights reserved