As the world undergoes a demographic transition characterized by simultaneous low fertility and population aging, Korea is experiencing this shift at a particularly rapid pace. These demographic changes are triggering extensive structural transformations across interest rates, growth, industrial structure, government finances, and external balances. This report quantitatively evaluates the impact of global demographic changes on five pillars of the Korean economy—neutral interest rates, productivity, industry and trade, public finance, and external sector—and presents integrated policy responses.

Chapter 2 demonstrates through a cross-country state-space model that Korea's long-term neutral interest rate has been structurally declining. Productivity slowdown, demographic transition (around 2015), and global safe asset supply-demand dynamics and their spillover channels have been identified as the primary determinants, with Korea's neutral rate continuing its downward trend even after COVID-19. Incorporating future domestic and global demographic projections, the neutral rate is likely to face additional downward pressure in the medium to long term.

Chapter 3 utilizes growth accounting and an OLG model to analyze how population aging reduces total factor productivity and output through decreased intangible asset investment efficiency. The analysis shows that a 10 percentage point decline in efficiency reduces TFP by 2%, while a 20 percentage point decline results in a 10% decrease in TFP and 6% in gross output, with even greater impacts at a 30 percentage point decline. However, low international interest rates in an open economy partially buffer these shocks through capital deepening, reducing the impact from 13% to 4% for TFP and from 14% to 4% for gross output even under extreme assumptions.

Chapter 4 demonstrates how the interaction between task skill intensity and age structure reshapes comparative advantages in trade. In a counterfactual scenario where only Korea ages, competitiveness risks increase in labor-intensive manufacturing. However, when considering simultaneous global aging, relative strengths may emerge in cognitive and technology-intensive manufacturing. The analysis confirms that sectors with higher shares of young and college-educated workers and greater capital intensity in equipment and intellectual property show significant correlation with export shares.

Chapter 5 shows that demographic changes alone will rapidly increase mandatory spending and reduce fiscal space, concluding that ensuring fiscal sustainability through tax increases alone is infeasible. In an open economy, the possibility of capital flight following capital income tax increases must also be considered, necessitating a medium- to long-term framework centered on expenditure efficiency, structural adjustment, and fiscal discipline.

Chapter 6 confirms through panel and polynomial age structure models that domestic demographics have nonlinear effects on the current account through savings-investment balance. Considering only domestic demographics, Korea's current account is expected to turn to deficit in 2041 with subsequent widening. However, when incorporating global demographic structures, international factors partially offset domestic effects, delaying the deficit transition to 2059—an 18-year postponement. While the trade balance is sensitive to demographics, the income balance depends on net foreign assets and returns, making income balance strengthening a crucial buffer mechanism.

Based on these analyses, the following policy implications emerge. First, in preparation for declining neutral rates, legal and institutional frameworks for unconventional monetary tools in zero lower bound environments should be established, range-based neutral rate estimation with continuous updates should be implemented, and policy coordination with fiscal and macroprudential measures should be strengthened. Second, as expanding intangible asset investment and improving efficiency are key to mitigating aging impacts, it is necessary to establish neutrality between tangible and intangible assets in taxation, accounting, and finance, expand diffusion infrastructure such as data and standards along with risk-sharing mechanisms, and strengthen lifelong learning and transition support. Third, industrial and trade strategies require enhancing competitiveness in cognitive and technology-intensive industries, expanding service tradability, and implementing tailored responses based on sector-specific value chain characteristics. Fourth, public finance must secure sustainability through expenditure efficiency, structural reform, and tax equity. Finally, external strategies should shift toward strengthening the income balance through increasing net foreign asset scale and returns to offset trade balance weakening.