The bar chart above illustrates the dynamic changes in mobile-phone subscriptions across developing and developed countries between 2000 and 2008.

As is clearly shown, a dramatic surge occurred in developing countries, where the number skyrocketed from 0.4 billion to 4 billion. By contrast, the figure for developed countries only experienced a marginal growth, plateauing at around 1 billion after 2002.

This striking divergence can be attributed to the following reasons. Primarily, the rapid economic growth in developing nations has catalyzed the massive expansion of telecommunication infrastructure, creating a vast market. Coupled with rising disposable incomes, an exponentially growing number of citizens could afford mobile phones. Furthermore, continuous technological advancements led to a substantial decline in production costs, making mobile devices increasingly accessible to the general public in these regions. Meanwhile, markets in developed countries had already reached...