総説・解説等 - 野村　浩二

"Half the Capital Stock, One Premise: Japan's ¥1 Quadrillion of Implicit Power-System Credit"

Koji Nomura

Productivity Research Notes （Keio Economic Observatory, Keio University）   （ 2619 ）  2026年08月

記事・総説・解説・論説等（大学・研究所紀要）, 単著

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Productivity Research Notes (PRN Series), No. 2619.
Reliable electricity at economically viable prices underpins long-lived capital. Using a bottom-up classification of more than 170 asset categories, this note estimates Japan's electricity-dependent capital stock at ¥1,000.8 trillion in 2019—49.8 percent of the measured stock of fixed assets, inventories, and household durables, and 1.8 times annual GDP—with a range of ¥403.4 to ¥1,830.7 trillion under alternative dependence weights. The measure captures neither outage losses nor physical damage; it quantifies an "implicit power-system credit" embodied in long-lived, partly irreversible investment commitments. The result motivates, but does not test, the hypothesis that weaker confidence in reliable and affordable electricity has contributed to Japan's weak capital accumulation and sluggish labor-productivity growth since the 2010s.

PRN2619

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「ZEB成功神話を疑う」

野村浩二

『エネルギー政策研究会 EP Report』 （エネルギーフォーラム社）   （ 2183 ）  2026年08月

記事・総説・解説・論説等（商業誌、新聞、ウェブメディア）, 単著

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本稿は、幸楽苑安積店のZEB Ready化を事例に、脱炭素政策の「成功事例」が何を証明しうるのかを検討する。設計上の省エネ性能、実際の運用効果、私的採算性、政策の追加性、他案件への反復可能性は必ずしも一致せず、さらに公表される実績は案件成立と社会的可視化という二重の選抜を経ている。こうした来歴と経済性を検証しないまま規制を強化すれば、費用負担や資本蓄積への影響を過小評価し、将来の生産性と所得を損なうおそれがある。

「無視できない産業空洞化－コストの現実直視を」（多事争論『日本成長戦略の読み方』）

野村浩二

『月刊エネルギーフォーラム』 （エネルギーフォーラム社）  860   112 - 113 2026年08月

記事・総説・解説・論説等（商業誌、新聞、ウェブメディア）, 単著

「土俵と市場」（時評ウェーブ）

野村浩二

『電気新聞』 （日本電気協会）   2026年07月

記事・総説・解説・論説等（商業誌、新聞、ウェブメディア）, 単著

"Higher GDP, Lower GDP per Capita: Population Coverage and Turkiye’s 2025 Benchmark Revision"

Koji Nomura

Productivity Research Notes （Keio Economic Observatory, Keio University）   （ 2618 ）  2026年07月

記事・総説・解説・論説等（大学・研究所紀要）, 単著

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Productivity Research Notes (PRN Series), No. 2618.
Turkiye’s 2025 benchmark revision raised nominal GDP but lowered GDP per capita because Syrians under temporary protection were added to the national-accounts population while the labor-force population remained unchanged. This note shows that the resulting population-coverage gap may overstate Turkiye’s measured labor productivity by roughly 2–4%, enough to affect its comparison with Japan. The evidence supports an explicit caveat rather than a formal correction to AQALI.

PRN2618

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"Converging Aggregates, Diverging Components: Iran’s 2021 Benchmark Revision"

Koji Nomura and Sho Inaba

Productivity Research Notes （Keio Economic Observatory, Keio University）   （ 2617 ）  2026年07月

記事・総説・解説・論説等（大学・研究所紀要）, 単著

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Productivity Research Notes (PRN Series), No. 2617.
Iran maintains two independent national accounts systems—SCI and CBI—whose GDP estimates differed by 38% under the previous benchmarks. The 2021 benchmark revision narrowed the gap to 20%, but this aggregate convergence is misleading. On the expenditure side, consumption and gross fixed capital formation reversed which series was larger, so the narrowing largely reflects offsetting movements rather than genuine agreement. On the production side, electricity remains a major outlier, with SCI’s estimate still 7.6 times that of CBI, plausibly reflecting different price-valuation bases. Inventory changes may also function as balancing items rather than measures of genuine stockbuilding. The note shows that aggregate convergence alone is not informative about measurement reliability; component-level diagnosis is required.

PRN2617

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"Interpreting PPPs under a Dual Exchange-Rate System: Evidence from Turkmenistan"

Koji Nomura

Productivity Research Notes （Keio Economic Observatory, Keio University）   （ 2616 ）  2026年06月

記事・総説・解説・論説等（大学・研究所紀要）, 単著

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Productivity Research Notes (PRN Series), No. 2616.
Applying a parallel-market exchange rate to the ICP PPP for GDP can imply an implausibly low price level, apparently suggesting that the PPP is underestimated. An exploratory price survey shows instead that the paradox reflects a mismatch between the economic transactions represented by PPPs and exchange rates. The note argues that meaningful international comparisons require matching PPPs and exchange rates to their intended economic transactions.

PRN2616

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"Broad Gains, Flat Aggregate: Industrial Structure and Japan’s Energy Productivity to 2040"

Koji Nomura

Productivity Research Notes （Keio Economic Observatory, Keio University）   （ 2615 ）  2026年06月

記事・総説・解説・論説等（大学・研究所紀要）, 単著

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Productivity Research Notes (PRN Series), No. 2615.
Under a technology-and-societal-implementation scenario (TSI) to 2040, evaluated with the SBI-FERI BIP model, energy productivity improves across most Japanese industries while the economy-wide measure barely moves (0.9% to 1.0% per year). This note shows that the near-flat aggregate reflects a structural shift toward more energy-intensive activity as manufacturing returns home, offsetting broad-based efficiency gains at the industry level. It extends the argument to emissions, where higher domestic emissions under TSI need not imply higher global emissions.

PRN2615

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"China’s Housing-Service Revision: Reconciling Official Statistics and International Productivity Databases"

Koji Nomura

Productivity Research Notes （Keio Economic Observatory, Keio University）   （ 2614 ）  2026年06月

記事・総説・解説・論説等（大学・研究所紀要）, 単著

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Productivity Research Notes (PRN Series), No. 2614.
China's 2023 GDP revision, released following the Fifth National Economic Census, raised nominal GDP by 2.7 percent, with a substantial share arising from the adoption of a rental-equivalence approach for owner-occupied housing services. While this change moves China's national accounts closer to international standards, important measurement issues remain. Since 2022, the APO Productivity Database (APO-PDB) has incorporated explicit housing-service adjustments for China. This note discusses how these adjustments can be reconciled with the revised official statistics and explains the treatment adopted in APO-PDB 2026 to maintain cross-country comparability.


PRN2614

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「譲れない安全はどこで止まるのか」

野村浩二

『視点・論点』 （日本政策投資銀行設備投資研究所）   2026年06月

記事・総説・解説・論説等（大学・研究所紀要）, 単著

"Intangible Expansion and Capital Quality: Implications of the 2020 Benchmark Revision in Japan"

Koji Nomura and Yutaka Suga

Productivity Research Notes （Keio Economic Observatory, Keio University）   （ 2613 ）  2026年06月

記事・総説・解説・論説等（大学・研究所紀要）, 共著

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Productivity Research Notes (PRN Series), No. 2613.
Japan's 2020 benchmark revision of the national accounts substantially expands measured intangible investment, with software investment alone accounting for roughly 1.5 percentage points of the 2.7% upward revision to 2020 nominal GDP. The adjustment is concentrated in the post-2015 period and markedly revalues the capital stock—software net stock rises by about 75% by end-2023. Because intangible assets carry higher depreciation rates and user costs, the revision raises the growth of capital services more than that of capital stock, widening the divergence between the two measures. In a Jorgensonian growth-accounting framework, this divergence—interpreted as capital quality—implies that a larger share of measured output growth is attributable to capital input rather than to residual total factor productivity. The revision therefore reframes Japan's recent growth performance as more capital-driven, with implications for both domestic analysis and cross-country comparisons.

PRN2613

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「測定なき経済学」（時評ウェーブ）

野村浩二

『電気新聞』 （日本電気協会）   2026年05月

記事・総説・解説・論説等（商業誌、新聞、ウェブメディア）, 単著

「非政府有志によるエネルギー基本計画」（第７版）

杉山大志・野村浩二(編著), 飯倉穣・ 岡芳明・ 岡野邦彦・ 加藤康子・ 小島正美・ 澤田哲生・ 巽直樹・ 田中博・ 戸田直樹・ 中澤治久・ 南部鶴彦・ 平井宏治・ 松田智・ 室中善博・ 薬師院仁志・ 山本隆三・ 山口雅之・ 渡辺正 (著)

 2026年05月

機関テクニカルレポート，技術報告書，プレプリント等, 共著

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第7版は、第6版から大幅に拡充。最大の変更点は現状認識I章の全面再編で、新たにI.2「気候変動の科学的知見」を独立章として新設（12節構成）。第6版II.10に収録されていた気候科学関連の節を移管・拡充し、気候科学そのものへの批判的検証を体系化した。I.1（脱炭素政策の弊害）には「日独における鉄鋼の生産減退」「再エネ主力電源化の問題点」「再エネ開発と地域社会の衝突」など3節を新設。第6版のI.2（人為的温暖化論の社会学）はI.3に繰り下げ「メディアと言論行動のメカニズム」「気候変動言論の構造的収斂」の2節を追加、I.3（世界的に後退する脱炭素政策）はI.4に繰り下げ欧州グリーン実験の総括・米国火力復活・2025年の転換点など3節を追加した。政策提言のII章では、化石燃料章（II.3）に「ホルムズ海峡危機対応」を冒頭節として新設し、電力需給シナリオ・石炭サプライチェーン・固定費回収問題など4節を追加。エネルギーコスト章（II.1）に「GXは戦後最大級の政策的失敗である」など3節を新設。自動車章（II.5）には「日本自動車産業の現状と競争力」を冒頭節として追加。省エネ規制章（II.7）は2節から4節に全面改訂。電気事業制度章（II.8）には「自由化10年の総括—官製市場の失敗」1節を新設した。

"AI Deployment and Productivity: Why Productivity Diffusion Takes Time"

Koji Nomura and Naoki Tatsumi

Productivity Research Notes （Keio Economic Observatory, Keio University）   （ 2612 ）  2026年05月

記事・総説・解説・論説等（大学・研究所紀要）, 共著

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Productivity Research Notes (PRN Series), No. 2612.
Generative AI capabilities are advancing rapidly, yet measurable productivity gains may diffuse more slowly across economies. This note argues that the key bottleneck lies not in frontier AI access itself, but in the organizational and deployment capabilities required to integrate AI into enterprise production systems. As firms devote substantial resources to systems integration, workflow redesign, governance adaptation, and deployment-related activities, part of AI's economic gains may initially be absorbed by organizational adjustment costs rather than appearing as broad productivity improvements. Moreover, because many deployment-related activities are service-intensive, firm-specific, and difficult to capture in conventional input measures, measured TFP growth during the AI diffusion process may carry an upward bias that obscures the true scale of underlying organizational transformation.

PRN2612

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「日本の原子力政策に欠けている視点」

野村浩二

『エネルギー政策研究会 EP Report』 （エネルギーフォーラム社）   （ 2175 ）  2026年05月

記事・総説・解説・論説等（商業誌、新聞、ウェブメディア）, 単著

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福島第一原発事故以降、日本では原子力をめぐる議論において「丁寧な説明」の重要性が重視されてきた。本稿は、問題の本質は現場の説明不足ではなく、安全水準をどのような比較考量のもとで決定するのかという判断軸とマネジメントの不在にあると論じる。Energy Policy誌に掲載された米国有権者調査を参照すると、人々は放射線リスクだけで原発を評価しているわけではなく、エネルギー安全保障、脱炭素、国際競争力などとの比較の中で判断していることが示される。さらに丸山眞男の「強靭な主体的精神」を手掛かりに、価値を固定化せず比較考量を行う主体の必要性を指摘する。安全性のみを絶対化する思考停止は、長期的には投資や供給力、技術革新を損ない、安全を支える基盤そのものを弱めかねない。

"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年05月

記事・総説・解説・論説等（大学・研究所紀要）, 共著

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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年05月

記事・総説・解説・論説等（大学・研究所紀要）, 単著

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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年05月

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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年04月

記事・総説・解説・論説等（大学・研究所紀要）, 単著

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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年04月

記事・総説・解説・論説等（大学・研究所紀要）, 共著

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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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