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Reviews, Commentaries, etc. - NOMURA Koji

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”A Perspective Missing from Japan's Nuclear Policy” (in Japanese)

Koji Nomura

Energy Policy Report (Energy Forum Inc.) ( 2175 ) 2026.05

Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

Since the Fukushima Daiichi accident, discussions on nuclear policy in Japan have emphasized the importance of “careful explanation” to society. This article argues that the central issue lies not in insufficient communication by frontline operators, but in the absence of a decision-making framework that evaluates safety levels through comparison with other risks and social costs. Referring to a recent survey experiment published in Energy Policy, the article shows that public support for nuclear power is shaped not only by perceptions of radiation risk, but also by comparisons with energy security, decarbonization, and international competitiveness. Drawing on Masao Maruyama’s idea of a “robust subjective spirit,” the article highlights the importance of continual comparative judgment rather than fixed and absolute values. It concludes that treating safety as unquestionable may ultimately weaken the economic and technological foundations necessary to sustain long-term safety itself.

"Quality Adjustment and PPP: A Fundamental Caveat in Productivity Comparisons"

Ho, Mun S., Koji Nomura, and Jon D. Samuels

Productivity Research Notes (Keio Economic Observatory, Keio University) ( 2611 ) 2026.05

Article, review, commentary, editorial, etc. (bulletin of university, research institution), Joint Work

Productivity Research Notes (PRN Series), No. 2611.
Cross-country productivity comparisons are fundamentally shaped by how national statistical agencies treat quality change in price indices. When quality improvements are incompletely captured, measured inflation is overstated and real output growth understated—with differences accumulating over time. Neither constant PPPs, which extrapolate from a benchmark year using national deflators, nor current PPPs, which incorporate updated international price data, can fully resolve these inconsistencies. Interpreting productivity level comparisons therefore requires careful attention to cross-country differences in price measurement methods.

PRN2611

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"Importing Bits, Not Watts: AI Infrastructure and Japan’s Electricity Constraint"

Koji Nomura

Productivity Research Notes (Keio Economic Observatory, Keio University) ( 2610 ) 2026.05

Article, review, commentary, editorial, etc. (bulletin of university, research institution), Single Work

Productivity Research Notes (PRN Series), No. 2610.
Artificial intelligence is increasingly discussed as a driver of future productivity growth, yet its expansion also depends on electricity supply and physical infrastructure. This note argues that AI computation can increasingly be traded internationally as digital services, while electricity supply remains geographically constrained. Using Japan as a case study, it examines how electricity costs, transmission limitations, and industrial linkages shape the domestic location of AI-related computation. The note further highlights the uncertainty surrounding future AI-related electricity demand, emphasizing both the evolving electricity productivity of computation and the uncertain long-run sustainability of rapidly expanding digital consumption patterns. These observations suggest that AI competitiveness may increasingly depend on stable, scalable, and economically sustainable electricity systems as much as on advances in computation itself.

PRN2610

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"Energy Cost Divergence and Industrial Adjustment: Evidence from Germany and Japan"

Koji Nomura and Sho Inaba

Productivity Research Notes (Keio Economic Observatory, Keio University) ( 2609 ) 2026.05

Article, review, commentary, editorial, etc. (bulletin of university, research institution), Joint Work

Productivity Research Notes (PRN Series), No. 2609.
This note examines how diverging energy cost conditions since the late 2010s have affected industrial activity in advanced economies, with a focus on Germany and Japan. Using high-frequency production indices, it documents a sustained contraction of energy-intensive and trade-exposed (EITE) industries and shows that the impact extends beyond directly exposed sectors. While Germany exhibits pronounced spillovers to non-EITE manufacturing, Japan shows more limited propagation, indicating heterogeneous economy-wide adjustment. Decomposition analysis reveals that these declines are broad-based across core sectors but differ in composition and temporal patterns, with closer alignment to energy price fluctuations in Germany and more linear adjustment in Japan. These findings suggest that recent changes reflect structural adjustment and production reallocation, with important implications for interpreting aggregate productivity dynamics.

PRN2609

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"Product Tax Measurement, GDP Revision, and Productivity: Evidence from Fiji"

Koji Nomura

Productivity Research Notes (Keio Economic Observatory, Keio University) ( 2608 ) 2026.04

Article, review, commentary, editorial, etc. (bulletin of university, research institution), Single Work

Productivity Research Notes (PRN Series), No. 2608.
This note examines the implications of Fiji’s 2019 national accounts rebasing for the measurement of value added and productivity. While GDP at market prices was revised downward, a larger decline in net taxes on products led to an upward revision in GDP at basic prices. With compensation of employees largely unchanged, the adjustment increases the measured capital income share. As productivity measurement relies on value added and its income components, such revisions affect growth accounting results. In Fiji, where labor input has grown faster than capital, the revision tends to reinforce the recent improvement in measured total factor productivity (TFP), although part of this may reflect demand-side factors. These findings highlight the importance of accurate tax measurement in national accounts.

PRN2608

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"Revisiting India’s Growth Pattern: GDP Rebasing and the Decline in Consumption Share"

Koji Nomura and Mun S. Ho

Productivity Research Notes (Keio Economic Observatory, Keio University) ( 2607 ) 2026.04

Article, review, commentary, editorial, etc. (bulletin of university, research institution), Joint Work

Productivity Research Notes (PRN Series), No. 2607.

This note examines the implications of India’s 2022–23 GDP rebasing for the composition of final demand and income. The revision leads to a substantial downward adjustment in household consumption and a corresponding increase in the investment share, suggesting that India’s growth has been less consumption-driven and more investment-oriented than previously indicated. The analysis highlights that these changes primarily reflect improvements in measurement—particularly the integration of supply–use tables and reduced reliance on residual balancing—rather than shifts in underlying economic behavior. On the income side, the reallocation within capital income and the decline in value added imply changes in measured income shares, with potential implications for growth accounting and the interpretation of productivity dynamics.

PRN2607

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"Mismeasuring Productivity in Resource-Rich Economies: Evidence from Saudi Arabia"

Koji Nomura and Sho Inaba

Productivity Research Notes (Keio Economic Observatory, Keio University) ( 2606 ) 2026.04

Article, review, commentary, editorial, etc. (bulletin of university, research institution), Joint Work

Productivity Research Notes (PRN Series), No. 2606.

This note shows that standard productivity measures can misrepresent economic performance in resource-rich economies when natural resource capital is omitted from growth accounting. Using evidence from Saudi Arabia, it demonstrates that mineral and energy resources (MER), particularly oil, are a dominant component of capital and materially affect measured capital services. When MER is excluded, TFP exhibits a pronounced decline from the late 2000s; incorporating MER instead stabilizes the TFP path and shifts its level upward, indicating that part of the observed decline reflects unmeasured resource depletion rather than true productivity losses. These results point to a structural measurement bias in conventional productivity analysis and underscore the need to integrate natural resource capital for consistent cross-country comparisons.

PRN2606

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"Can you believe the price?" (in Japanese)

Koji Nomura

Wave (Denki Shimbun) (The Denki Shimbun) 2026.04

Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

"Income Concepts and Productivity: Separating Production from Asset Revaluation and Its Implications for TFP"

Koji Nomura

Productivity Research Notes (Keio Economic Observatory, Keio University) ( 2605 ) 2026.04

Article, review, commentary, editorial, etc. (bulletin of university, research institution), Single Work

Productivity Research Notes (PRN Series), No. 2605.
This note examines how alternative definitions of income and production—particularly the treatment of asset revaluation—affect the interpretation of TFP. Drawing on the framework of Diewert and Fox (2024), it emphasizes that SNA-based and Hicksian income concepts define distinct accounting objects rather than alternative measures of the same construct. It shows that including or excluding asset revaluation shifts the boundary between production and income, thereby changing the economic content of TFP. Removing revaluation effects from production reduces the influence of asset price fluctuations on capital input prices and yields a more stable indicator of production efficiency. The note underscores the need for conceptual alignment in cross-country and intertemporal productivity comparisons, particularly in economies with large asset shares such as land.

PRN2605

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"Measuring Labor Share in Economies without COE: A Bottom-Up Approach in Vietnam"

Koji Nomura

Productivity Research Notes (Keio Economic Observatory, Keio University) ( 2604 ) 2026.03

Article, review, commentary, editorial, etc. (bulletin of university, research institution), Single Work

Productivity Research Notes (PRN Series), No. 2604.
This note develops a bottom-up approach to measuring labor share in economies where compensation of employees (COE) is not available in national accounts, using Vietnam as a case study. By integrating micro-level data on wages, employment, and hours worked, it constructs consistent time-series estimates of labor compensation and factor income shares. The results show that the derived labor share aligns with available benchmark aggregates while remaining conceptually distinct from mixed income measures. The analysis further demonstrates that uncertainty in labor share measurement translates directly into substantial variation in total factor productivity (TFP) estimates, underscoring the importance of reliable labor compensation data for growth accounting in developing economies.

PRN2604

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"Beyond Energy Prices: Strait Closure Risk in Asian Supply Chains, with Evidence from Energy Productivity"

Koji Nomura

Productivity Research Notes (Keio Economic Observatory, Keio University) ( 2603 ) 2026.03

Article, review, commentary, editorial, etc. (bulletin of university, research institution), Single Work

Productivity Research Notes (PRN Series), No. 2603.
This note examines the economic implications of a potential Strait of Hormuz closure, emphasizing that the primary risk extends beyond energy price increases to the disruption of Asian supply chains. As global production networks deepen, energy shocks propagate through intermediate goods trade, disrupting downstream manufacturing before price effects become binding. Using cross-country evidence on energy productivity, the note highlights structural differences in vulnerability across Asian economies. It also revisits the role of strategic reserves, arguing that they function as insurance against physical supply disruption rather than as tools for price stabilization. The analysis suggests that policy frameworks may underestimate supply chain transmission risks and over-rely on reserves for managing price pressures.

PRN2603

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"Can AI Revive Japan's Productivity?: Technology Implementation Scenario to 2040"

Koji Nomura

Productivity Research Notes (Keio Economic Observatory, Keio University) ( 2602 ) 2026.03

Article, review, commentary, editorial, etc. (bulletin of university, research institution), Single Work

Productivity Research Notes (PRN Series), No. 2602.
This note examines the potential impact of artificial intelligence (AI) on Japan’s productivity under a technology implementation scenario to 2040. Using a growth accounting and general equilibrium framework, it evaluates how the diffusion of AI-related technologies across sectors—together with complementary investment, institutional reform, and stable electricity supply—affects total factor productivity (TFP) and economic growth. The results suggest that productivity gains arise from the combined implementation of multiple technologies rather than a single innovation, with manufacturing playing a central role in driving economy-wide efficiency improvements.

PRN2602

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"Reshaping Asia’s Economic Landscape: PPP Revisions and Level Comparisons"

Koji Nomura and Mun S. Ho

Productivity Research Notes (Keio Economic Observatory, Keio University) ( 2601 ) 2026.03

Article, review, commentary, editorial, etc. (bulletin of university, research institution), Joint Work

PRN2601

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”Can Artificial Intelligence Become the Modern Atlatl?” (in Japanese)

Koji Nomura

Energy Policy Report (Energy Forum Inc.) ( 2167 ) 2026.02

Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

The atlatl, a spear-throwing device used during the North American Archaic period, not only increased projectile velocity, range, and accuracy compared with hand-thrown spears, but experimental evidence also suggests that it statistically reduced differences in physical strength between men and women, allowing a wider range of individuals to participate in hunting activities. In the twenty-first century, could artificial intelligence become a modern atlatl that similarly narrows capability gaps? The Industrial Revolution, the electrification revolution, and the information revolution may once again converge through technological advances such as AI, potentially producing structural transformations on an unprecedented scale. At the SBI Institute for Financial Economics, the authors have developed a high-resolution general equilibrium model (BIP) and conducted scenario analyses of the Japanese economy in 2040, exploring the possibility of nominal GDP approaching one quadrillion yen. Technological innovation driven by AI is often discussed in connection with concerns about job losses and widening income inequality. However, scenario analyses using the BIP model suggest that even under accelerated innovation scenarios, large-scale employment declines in manufacturing and finance can be macroscopically absorbed through job creation in other sectors accompanying faster economic growth. Technological innovation raises the productivity of older workers and women, and even as working hours decline, hourly wage rates rise faster than the average, expanding total labor income. In terms of distribution, the results differ from the conventional narrative of skill-biased technological change: broad wage increases, including among blue-collar workers, lead to a declining share of low-income groups. AI-driven technological innovation therefore has the potential to reshape social structures as a modern atlatl. The equalizing effects attributed to the ancient atlatl did not arise automatically; they functioned only when appropriate social conditions existed. Whether AI can serve as a modern atlatl likewise depends heavily on the development of social and institutional capital. In scenarios of innovative growth for the Japanese economy, increases in value added appear primarily in the service sector, yet the core growth mechanism remains rooted in manufacturing. The effective realization of technological innovation requires the revitalization of production networks centered on manufacturing. Data centers—essential for meeting the expanding demand for information services that support this ecosystem—depend fundamentally on affordable and stable electricity supply. In economies where electricity prices are volatile and supply margins are limited, AI investment tends to amplify intersectoral distortions, preventing the expected economy-wide productivity gains from emerging. Current decarbonization policies move in the opposite direction. Institutional frameworks such as the GX-ETS, introduced without sufficient international coordination, increase uncertainty regarding both electricity prices and supply, severely undermining investment predictability for industry and data centers. In energy-intensive manufacturing sectors, subsidies are directed toward technological development with uncertain demand prospects while production activities are simultaneously incentivized to relocate overseas. Technological innovation cannot take root without the necessary social and economic conditions. A failure of energy policy, therefore, is effectively equivalent to depriving society of AI as the modern atlatl.

"Conciseness and accuracy" (in Japanese)

Koji Nomura

Wave (Denki Shimbun) (The Denki Shimbun) 2026.02

Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

"Value of Nuclear Power Undermined by Decarbonization Policy"

Koji Nomura

Journal of the Atomic Energy Society of Japan: ATOMOΣ (Atomic Energy Society of Japan) 68 ( 2 ) 62 - 63 2026.02

Article, review, commentary, editorial, etc. (scientific journal), Single Work

The Takaichi administration has so far maintained the conventional policy approach of pursuing both stable energy supply and decarbonization simultaneously, utilizing the GX budget framework. However, this strategy carries a substantial risk of producing outcomes that run counter to the administration’s stated objective of achieving a “strong economy.”

For decarbonization policies to be compatible with a strong economic foundation, two conditions are necessary: internationally harmonized allocation of emission burdens and substantial cost reductions in decarbonization technologies. At present, neither condition is satisfied. As a result, carbon leakage has accelerated the hollowing out of domestic industry, and production in energy-intensive industries in both Japan and Germany has fallen by roughly 20 percent compared with 2018 levels.

Moreover, decarbonization policies have begun to distort the electricity system itself. The consumer surplus historically generated by nuclear power is increasingly diverted to subsidize renewable energy integration, thereby eroding the very value that nuclear power originally provided—reliable and low-cost electricity supply.

Given these developments, it is necessary to apply the precautionary principle to the significant and potentially irreversible risks associated with continuing the current GX policy trajectory. A strategic shift away from existing decarbonization policies should therefore be considered.

"Japan at Its Cultural Edges" (in Japanese)

Koji Nomura

Wave (Denki Shimbun) (The Denki Shimbun) 2025.12

Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

"Sound Skepticism" (in Japanese)

Koji Nomura

Wave (Denki Shimbun) (The Denki Shimbun) 2025.11

Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

”A Shift Away from Current Decarbonization Policies Essential to Sanae's Economic Agenda” (in Japanese)

Koji Nomura

Energy Policy Report (Energy Forum Inc.) ( 2159 ) 2025.11

Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

The Japan-U.S. summit between Prime Minister Takaichi and President Trump produced a joint fact sheet on bilateral investment that outlined a framework for cooperation on nuclear energy development and energy infrastructure investment. As Japan works to align its energy policy with the U.S. administration's energy dominance agenda, a broader shift away from decarbonization policy may follow. Such a shift would not only serve to deepen the Japan-U.S. alliance but could also lay the foundation for realizing Sanaenomics, Prime Minister Takaichi's economic growth-oriented agenda. The area Prime Minister Takaichi placed greatest emphasis on was the expanded utilization of nuclear power, with a notable feature being her commitment to not only new construction and capacity additions but also the early commercialization of next-generation advanced reactors and fusion energy. Going forward, however, two points warrant careful attention in advancing nuclear energy. The first is that promoting nuclear power is no longer compatible with decarbonization policy. Under current policy, the push for nuclear has been justified by its value as a low-carbon power source, but nuclear energy's far greater value lies in its capacity for stable supply. In Europe, where ideals were pursued ahead of any internationally coordinated framework for equitably sharing the burden, and in Japan, which followed suit, the hollowing-out of energy-intensive industries has become strikingly pronounced over just the past few years. Once such industries relocate abroad, they do not return easily. The continuation of decarbonization policy is also diminishing the value of nuclear power itself, by driving away the very industrial consumers that depend on stable supply. Nuclear energy only makes sense atop a strong industrial base, and halting the erosion of that base must be treated as an urgent priority in any effort to revive a robust economy.
The second point is the need to once again separate technology development support from energy policy proper. Supporting research and development is a legitimate role of government, but the success of those efforts should not be baked into energy policy as a given, given its profound impact on the real economy. Even if fusion energy comes online decades from now, the electricity price achievable even under the most optimistic scenario — where all currently envisioned technologies succeed — is expected to be roughly on par with existing nuclear plants. We are not heading toward a world where electricity prices approach zero. Prime Minister Takaichi stated her strong opposition to "covering Japan's beautiful landscape with foreign-made solar panels" and called for a thorough "housecleaning" of renewable energy subsidy schemes. Alongside this, she indicated support for the development and deployment of perovskite solar cells, but the dilemma remains: even if domestically produced, expensive panels would ultimately expand the burden on electricity consumers. The primary factor behind defeat in competition with China is neither labor costs nor managerial efficiency — it is the highly predictable demand artificially created by policy. Chinese companies can sustain a game of chicken until private-sector competitors from democratic nations are forced to withdraw, then "wait for their moment" to recover losses after rivals exit the market. It is the decarbonization policies of advanced economies that have sustained the viability of business models that disregard the cost of capital. The U.S. policy shift will dissolve this artificially engineered predictability and return demand to consumer sovereignty. Calls for domestic production while maintaining decarbonization policy will amount to nothing more than castles in the air.

"The Impact of Surging Electricity Prices"

Koji Nomura

『月刊エネルギーフォーラム』 (エネルギーフォーラム社) ( 10月 ) 2025.10

Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

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