How does aging affect government activities? This chapter empirically analyzes this concern by focusing on public spending, such as public investment. Some studies have confirmed that aging negatively impacts public spending that brings long-term benefits for us. Jäger and Schmidt (2016) show that aging negatively impacts investments of public capital. Instead, studies on public capital investments in Japan have focused on their productivity and efficiency. Some of these studies show that Japan’s public capital investment was performed inefficiently and allocated unfairly across regions. This biased regional allocation is attributed to political processes. In this chapter, we analyze public capital investment from the perspectives of both aging and regional allocation.