|
on Investment |
| By: | David Neumark; Emma Wohl |
| Abstract: | We provide the first direct estimates of the effects of minimum wages on low-wage workers in families at different points of the distribution of income-to-needs, using data from the Survey of Income and Program Participation, which oversamples low-income families. We find adverse – rather than beneficial – effects of minimum wages on the employment, hours, and earnings of initially-employed low-wage workers in poor and low-income families. Although we do not find a gradient indicating more adverse effects on the poorest low-wage workers, the adverse effects for poor and low-income low-wage workers help explain why minimum wages do not reduce poverty. |
| JEL: | J23 J38 |
| Date: | 2026–08 |
| URL: | https://d.repec.org/n?u=RePEc:nbr:nberwo:35628 |
| By: | Rahmarani, Anissa; Indrajaya, Danang |
| Abstract: | Efficient management of state-owned assets (Barang Milik Negara, BMN) is a critical determinant of fiscal accountability and non-tax state revenue (Penerimaan Negara Bukan Pajak, PNBP) optimization in public sector organizations. This study examines the process of proposing, verifying, and executing the sale and write-off of low-value BMN (below IDR 100 million) at the Bureau of Finance and State Assets, Secretariat General, Indonesia's Ministry of Communication and Digital Affairs (KOMDIGI), where delegated approval authority under Minister of Finance Regulation (PMK) No. 4/PMK.06/2015 was, in practice, insufficiently leveraged to accelerate administrative throughput. Employing a qualitative, participant-observation-based case study design conducted over a six-week practicum period, this research applies Business Process Mapping (As-Is vs. To-Be) to document the existing workflow, identify bottlenecks and non-value-added activities, and design a redesigned process architecture. The As-Is analysis reveals three structural inefficiencies: (1) duplicated manual verification between spreadsheet-based checklists and the State Asset Management Information System (SIMAN); (2) recurrent data mismatches across unit nomenclature, asset codes, and book values; and (3) an undifferentiated verification pathway that fails to exploit the risk-based delegation of authority for low-value assets. A SWOT matrix further situates these findings within the organization's internal capabilities and external opportunities, generating SO, WO, ST, and WT strategic alternatives. The proposed To-Be process (anchored on system integration, a risk-based fast-track lane, and standardized correspondence templates) is theorized to compress processing lead time and thereby preserve the economic value of assets pending disposal, directly reinforcing recovery value and PNBP contributions. This study contributes to the limited empirical literature on business process reengineering in Indonesian public asset governance and offers a replicable diagnostic-to-design framework for other line ministries operating under similarly delegated regulatory regimes. |
| Date: | 2026–08–15 |
| URL: | https://d.repec.org/n?u=RePEc:osf:socarx:r7b3s_v1 |
| By: | Kadriu, Valon |
| Abstract: | The scientific community rewards priority: the researcher who establishes a novel finding first, claims credit that later entrants cannot. This reward may increase the incentive to reach statistical significance. Using 43, 140 tests published in the AER, JPE, and QJE between 2001 and 2010, together with text-based and bibliographic measures of novelty, I examine whether more novel articles are more prone to selective reporting. Running caliper regressions around conventional significance thresholds, I find suggestive evidence that novel articles are more likely to report just-significant results at the 10 percent level, an association concentrated around the threshold and driven by textual novelty. |
| Keywords: | novelty, selective reporting, science of science |
| JEL: | A11 A14 C12 O31 |
| Date: | 2026 |
| URL: | https://d.repec.org/n?u=RePEc:zbw:i4rdps:310 |
| By: | Balán, Pablo; Bergeron, Augustin; Tourek, Gabriel; Weigel, Jonathan |
| Abstract: | Formal property rights to land remain rare in sub-Saharan Africa. We argue that social institutions shape citizens' demand for land formalization. When offered the opportunity to formalize, citizens weigh the insurance and tenure-security benefits of informal institutions against their monetary and social obligations. We study a randomized land titling program in a large Congolese city that sharply reduced the costs of acquiring a title. The program caused large increases in both initiation and receipt of titles. Demand was strongest among citizens more engaged in social institutions and more connected to city chiefs, yet such ties did not predict completion of the titling process. Program assignment also reduced citizens' participation in social institutions and worsened their evaluations of chiefs. These findings suggest that, in urban settings where land values are higher and social institutions are more costly, citizens may exit social institutions when formal alternatives become available, illustrating how formalization can reshape engagement with informal authority. |
| Date: | 2026 |
| URL: | https://d.repec.org/n?u=RePEc:zbw:cbscwp:342513 |
| By: | Ha Minh Nguyen |
| Abstract: | How do demographic trends shape the adoption of AI and automation technologies? This paper provides the first large-scale cross-country firm-level test of the demographic–automation hypothesis using World Bank Enterprise Surveys data covering 89, 380 firms across 144 countries from 2022 to 2025. I classify adopters by applying a large language model to firms’ open-ended process innovation descriptions, identifying 1, 656 AI and automation adopters (1.9 percent of the sample). A ten-percentage-point increase in the old-age dependency ratio raises process adoption probability by approximately 0.6 percentage points, after accounting for countries’ income levels, digital infrastructure, firm size and sector, and broad regional and time differences. The result is robust across specifications and supported by an instrumental variable strategy based on predetermined demographic cohort structure. Heterogeneity analysis shows the effect concentrates in manufacturing, large firms, and developing economies for the broad adoption measure; restricting to firms with explicit references to AI reverses the sector pattern, with services firms significantly more likely to adopt than manufacturing firms, pointing to distinct sectoral profiles for software-based AI and hardware-based automation. Aging also predicts firms’ development of AI-enabled products across both manufacturing and services. The results indicate that demographic aging shapes AI and automation adoption through both process and product innovation channels: firms substitute technology for increasingly scarce and costly labor in production, and separately develop AI-enabled products for labor-constrained customers. |
| Keywords: | Aging; automation; artificial intelligence; firm-level; technology adoption; labor-saving technology; World Bank Enterprise Surveys; demographics; labor substitution |
| Date: | 2026–08–21 |
| URL: | https://d.repec.org/n?u=RePEc:imf:imfwpa:2026/176 |
| By: | Yuanyuan Shen; Yiren Yan; Wenjie Li; Chunhui Zhu |
| Abstract: | On two-sided content platforms, symmetric two-sided isolation (assigning matched fractions of creators and viewers to isolated treatment and control submarkets) is widely used for creator-side and cold-start experiments because it removes cross-arm marketplace interference. Isolation, however, thins each viewer's candidate catalog, and intuition suggests the resulting engagement cost should fade as the platform grows: a small fraction of a vast catalog is still vast. We show that, in an order-statistics model of engagement, whether this intuition holds depends on the upper tail of match quality. Extreme-value theory yields tail-class loss laws with a sharp dichotomy: for light or bounded tails the loss vanishes as the candidate pool grows, whereas under heavy tails it converges to a size-independent constant, so expanding the candidate pool, even by orders of magnitude, does not asymptotically eliminate the cost. Evidence from two production experiments on a platform with millions of active creators is consistent with this picture: a pure A/A traffic sweep reveals a measurable, depth-graded engagement cost; a one-sided catalog ablation independently shows that per-viewer thinning contributes to the loss; and a tail index calibrated on the small exploration pool predicts an effect consistent with the one observed in the far larger full-catalog ablation. Isolation thus carries a price that experimenters should budget for, like any other cost. We give practitioners a preflight procedure that estimates it before launch, sizes traffic accordingly, and recommends a fallback design when the predicted cost exceeds a chosen tolerance. |
| Date: | 2026–08 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2608.04432 |
| By: | Imane Sridi (Laboratoire LISMAD, Faculté des Sciences Juridiques, Économiques et Sociales Aïn Sebaâ, Université Hassan II de Casablanca, Maroc); Lahcen Rachyq; Abdellah Labdaoui; Omar Essardi |
| Abstract: | In the era of digital transformation, technological advances are profoundly reshaping family dynamics, educational practices, and social behaviors. The widespread adoption of digital technologies, including connected devices, educational platforms, social media, and communication applications, has significantly influenced family interactions, children's socialization processes, and the transmission of values and social norms. While these technologies provide valuable opportunities by facilitating access to knowledge, promoting interactive learning, and strengthening intergenerational communication, they also raise concerns regarding their effects on children's cognitive, emotional, and social development, as well as on the quality of family relationships. This article presents an integrative narrative review of the theoretical and empirical literature on the impact of digital technologies on childhood and family life. Drawing on perspectives from family sociology, developmental psychology, and educational sciences, it examines the transformations driven by the rapid expansion of digital technologies. The study aims to identify the main trends highlighted in recent research and to explore their implications for family relationships, educational practices, and demographic changes. It also discusses the challenges faced by contemporary families while emphasizing the opportunities offered by digital technologies to promote children's development and well-being in an increasingly digital environment. Although a substantial body of research has examined the effects of digital technologies on children or on educational practices separately, relatively few studies provide an integrated analysis that simultaneously addresses the transformations of family relationships, educational practices, and child development. This article seeks to fill this gap by offering a critical, interdisciplinary synthesis of the existing literature. |
| Abstract: | À l'ère de la transformation numérique, les avancées technologiques redéfinissent profondément les dynamiques familiales, les pratiques éducatives et les comportements sociaux. La diffusion massive des technologies numériques, notamment les écrans connectés, les plateformes éducatives, les réseaux sociaux et les applications de communication, influence de manière significative les interactions au sein de la famille, les modes de socialisation des enfants ainsi que les mécanismes de transmission des valeurs et des normes. Si ces outils offrent de nombreuses opportunités en favorisant l'accès au savoir, l'apprentissage interactif et le renforcement de la communication entre les générations, ils suscitent également des préoccupations relatives à leurs effets sur le développement cognitif, émotionnel et social des enfants, ainsi que sur la qualité des relations familiales. Cet article propose une revue narrative intégrative de la littérature théorique et empirique consacrée à l'impact du numérique sur l'enfance et la famille. Il mobilise des approches issues de la sociologie de la famille, de la psychologie du développement et des sciences de l'éducation afin d'analyser les transformations engendrées par l'essor du numérique. L'objectif est d'identifier les principales tendances observées dans les recherches récentes et d'examiner leurs implications sur les relations familiales, les pratiques éducatives et les évolutions démographiques. L'étude met également en évidence les défis auxquels sont confrontées les familles contemporaines, tout en soulignant les opportunités offertes par les technologies numériques pour favoriser le développement et le bien-être des enfants dans un environnement en constante mutation. Peu d'études proposent une analyse intégrée mettant simultanément en perspective les transformations des relations familiales, des pratiques éducatives et du développement de l'enfant, Malgré l'abondance des travaux consacrés aux effets du numérique sur les enfants ou sur les pratiques éducatives. Cet article dans ce contexte vise à combler cette lacune en proposant une synthèse critique et pluridisciplinaire des travaux existants. |
| Keywords: | Parental mediation, Socialisation numérique médiation parentale parentalité numérique pratiques éducatives, structure familiale JEL Classification : F68, Family structure. Classification JEL: F68, Educational practices, Digital parenting, I21, K36 Type du papier : Recherche Théorique Digital socialization, pratiques éducatives, parentalité numérique, médiation parentale, Socialisation numérique, K36, K36 Type du papier : Recherche Théorique Digital socialization Parental mediation Digital parenting Educational practices Family structure. Classification JEL: F68, K10, K00 |
| Date: | 2026–08–13 |
| URL: | https://d.repec.org/n?u=RePEc:hal:journl:hal-05719048 |
| By: | Axel Durand Semboung (Université de Douala, Faculté des Sciences Économiques et Gestion Appliquée, Douala, Cameroun); Vatis Christian Kemezang (Université de Douala, Faculté des Sciences Économiques et Gestion Appliquée, Douala, Cameroun) |
| Abstract: | Migrant remittances constitute a major source of external financing in Sub Saharan Africa, yet the mechanisms through which they contribute to inclusive growth remain insufficiently established. This study examines their relationship with inclusive growth and identifies the main transmission channels. The analysis uses a balanced panel of 33 Sub Saharan African countries observed from 2000 to 2022, comprising 665 country year observations. Inclusive growth is measured using a composite index incorporating economic and social dimensions. The empirical strategy relies on multiple mediation analysis estimated through sequential regressions. The main equations are estimated by ordinary least squares with HC3 robust standard errors. Inference on indirect effects is based on 1, 000 country clustered bootstrap replications and 95% percentile confidence intervals. The results show a positive and statistically significant association between remittances and inclusive growth (β = 0.252, p < 0.01). Among the mechanisms examined, only productive investment exhibits a significant indirect effect. Human capital, financial development, and tax revenue do not significantly transmit this relationship. These findings show that the contribution of remittances to inclusive growth depends on the channel through which these resources affect the economy. They therefore highlight the need for policies that encourage the allocation of remittance inflows toward productive investment to strengthen their contribution to more inclusive and sustainable development. |
| Abstract: | Les transferts de fonds des migrants constituent une source majeure de financement extérieur en Afrique subsaharienne, mais les mécanismes par lesquels ils contribuent à la croissance inclusive restent insuffisamment établis. Cette étude analyse leur relation avec la croissance inclusive et identifie les principaux canaux de transmission. L'analyse porte sur un panel équilibré de 33 pays d'Afrique subsaharienne observés entre 2000 et 2022, soit 665 observations pays années. La croissance inclusive est mesurée à l'aide d'un indice composite intégrant des dimensions économiques et sociales. La stratégie empirique repose sur une analyse de médiation multiple par régressions séquentielles. Les équations principales sont estimées par moindres carrés ordinaires avec erreurs standards robustes HC3. L'inférence sur les effets indirects repose sur un bootstrap par grappes au niveau des pays comportant 1 000 réplications et des intervalles de confiance percentile à 95 %. Les résultats montrent une association positive et statistiquement significative entre les transferts de fonds et la croissance inclusive (β = 0, 252 ; p < 0, 01). Parmi les mécanismes examinés, seul l'investissement productif présente un effet indirect significatif. Le capital humain, le développement financier et les recettes fiscales ne transmettent pas significativement cette relation. Ces résultats montrent que la contribution des transferts à la croissance inclusive dépend du canal par lequel ces ressources affectent l'économie et soulignent la nécessité de politiques favorisant leur orientation vers des investissements productifs. |
| Keywords: | I32, Transferts de fonds, Croissance inclusive, M41, Sub-Saharan Africa Classification JEL : F24, M41 Remittances, C33, Investissement productif, O55, O15, Afrique subsaharienne. JEL Classification : F24, Sub-Saharan Africa Classification JEL : F24 O15 O55 I32 C33 M41, Human Capital, Productive Investment, Inclusive Growth, Afrique subsaharienne. JEL Classification : F24 O15 O55 I32 C33 M41 Remittances, Capital humain |
| Date: | 2026–07–10 |
| URL: | https://d.repec.org/n?u=RePEc:hal:journl:hal-05689191 |
| By: | Amadeo Grob; Maurizio Daniele; Johanna Ziegel |
| Abstract: | Traditional statistical tests are poorly suited for the sequential evaluation of probabilistic forecast calibration. We address this limitation in macroeconomic forecasting by applying a new sequential testing method based on e-values. The e-value-based methodology enables anytime-valid inference. It allows practitioners to test against calibration continuously without invalidating statistical guarantees. To illustrate the framework's practical value, we apply it to probabilistic inflation forecasts for the United States, the Euro Area, and Switzerland. Our analysis shows that the sequential approach gives detailed insights into the timing and nature of forecast misspecification. We find these diagnostics are particularly insightful during major structural breaks. During these events, we find evidence against calibration that static, full-sample tests often miss. Therefore, this work shows that e-value-based tests are a practical method for the evaluation of forecast calibration in empirical macroeconomics. |
| Date: | 2026–08 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2608.23064 |
| By: | Altin, Mehmet Evrim; Jäger, Kirsten; Jütte, Silke; Schneider, Florian |
| Abstract: | The rapid diffusion of artificial intelligence (AI) tools is fundamentally reshaping learning practices in higher education, particularly in mathematics and statistics courses. This study investigates how undergraduate students across multiple programs at IU International University engage with AI-based mathematics tools, which applications they prefer, and how they evaluate their performance. Drawing on survey data from 174 students enrolled in mathematics lectures during the spring term of 2025, we analyze awareness, usage intensity, and perceived usability, understandability, correctness, and value for money of leading AI tools. The results reveal a highly concentrated market structure: ChatGPT, Photomath, and Gemini dominate student awareness and usage. While ChatGPT is perceived as the most user-friendly and offers strong value for money, Photomath receives the highest ratings for correctness of results. Gemini, in contrast, is evaluated more cautiously across dimensions. Differences in awareness between mathintensive and non-math-intensive programs are small and statistically insignificant, suggesting that AI adoption in mathematics is broadly distributed across disciplines. The findings indicate that students integrate AI tools primarily as complementary learning aids rather than replacements for traditional materials. Overall, the study provides an empirical baseline for understanding how AI functions as a study partner in mathematics education and highlights the growing importance of evaluating not only usage frequency but also perceived reliability and pedagogical value. |
| Keywords: | Artificial Intelligence, Mathematics Education, Student Perceptions, Learning Tools |
| JEL: | I21 I23 O33 A22 C83 |
| Date: | 2026 |
| URL: | https://d.repec.org/n?u=RePEc:zbw:iubhbm:342564 |
| By: | Benjamin E. Radoc, Jr. (Bangko Sentral ng Pilipinas); Sarah Lynne S. Daway-Ducanes (University of the Philippines School of Economics) |
| Abstract: | The important role of expectations in intertemporal decision making has long been recognized but disagreement among economists on how expectations are formed persists. We conducted an online learning to forecast experiment to determine the impact of uncertainty (in terms of market volatility and number of players) and anchoring (or a non-binding target price band) on the quality of price forecasts. We find that forecast errors are significantly higher in more volatile markets; lower in the presence of a non-binding price bandwidth, suggesting an anchoring effect on expectations; and lower in later markets, confirming the importance of learning and e xperience. Employing a two-step system generalized method of moments, we further confirm these results, and also find that players make systematic forecast errors, in contrast to what is predicted by rational expectations hypothesis. |
| JEL: | C91 E31 E71 |
| Date: | 2025–01 |
| URL: | https://d.repec.org/n?u=RePEc:bhd:dpaper:202504 |
| By: | Abdelaaziz Ait Ali; Mahmoud Arbouch; Fahd Azaroual; Karim El Aynaoui; Adnane Lahzaoui |
| Abstract: | Morocco offers a compelling example of how a middle-income economy can navigate a more fragmented global environment, characterized by weak growth and slower convergence. Since 2022, economic activity has remained relatively strong, with growth exceeding that of many comparable economies. Non-agricultural growth has averaged 4.4% since 2022, around 1.3 percentage points above its historical average, and has accelerated to 4.8% since 2024. This performance has allowed Morocco to gradually recover from output losses incurred during the pandemic. The recovery has been mainly driven by capital accumulation, supported by a strong public investment effort and an investment rate expected to remain close to 30% of GDP. Yet this pattern also raises a familiar issue: investment-led growth can generate limited domestic spillovers when it relies heavily on imports. This weakens its impact on local production and puts pressure on the external balance. Consequently, net exports have continued to weigh on growth despite the solid performance of export-oriented sectors. At the same time, the external environment has also opened new opportunities. The reconfiguration of global value chains has increased Morocco’s attractiveness for foreign direct investment, particularly from China. In parallel, resilient remittances from Moroccans living abroad and more favorable terms of trade have supported income and domestic demand. The key concern now lies in the sustainability of this trajectory. Maintaining the current pace will require Morocco to convert the public investment impulse into stronger private investment and productivity gains, to support a structural transformation that remains incomplete. This transformation will also need to be reconsidered considering the demonstrated potential of certain tradable service activities, whose role could complement traditional manufacturing drivers. Otherwise, the current recovery may remain a phase of sustained growth, but without a sufficiently durable anchor. |
| Date: | 2026–07 |
| URL: | https://d.repec.org/n?u=RePEc:ocp:rpaeco:pp17_26 |
| By: | Tao, Yingnian (Lancaster University); Ryan, Mark |
| Abstract: | Corporations’ sustainability communication is increasingly challenged by digital publics. Yet research on how netizens contest corporate sustainability narratives, and thereby construct environmental meanings, remains largely confined to Western contexts. This study addresses this gap by examining Chinese netizens’ discursive responses to a controversial fireworks display in the Himalayas staged by international mountaineering brand Arc’teryx. Comments from the seven most popular Weibo posts were selected to compile a corpus (140, 584 tokens), and analysed through corpus-assisted discourse analysis, particularly keyword and concordance analysis. Findings show that netizens mobilise multiple meaning systems to express strong disapproval, including scientific ecological knowledge, perceptions of environmental governance failure, spiritual-cultural references, consumer action, and nationalism. These interconnected meaning systems converge around a distinctive feature of Chinese digital environmentalism: a nature-centred view of human-nature relations and harmony. The study extends understanding of digital environmentalism beyond Western contexts by showing that environmental meanings in Chinese digital spaces are place- and culture-based, intertwining ecological concerns with emotion, spiritual wellbeing, perceptions of justice, and national interests. |
| Date: | 2026–08–11 |
| URL: | https://d.repec.org/n?u=RePEc:osf:socarx:dr9z3_v2 |
| By: | Hanming Fang; Chang Liu |
| Abstract: | Total fertility rates in East Asia have fallen to levels without historical precedent, even though the region’s Confucian heritage long placed extraordinary emphasis on family continuity and large families. We argue that this “Confucian Fertility Paradox” dissolves once we separate two strands of the tradition and recognize that modernization affected them very differently. The pro-natal strand, built on lineage continuity, ancestor worship, and reliance on sons for old-age support, was gradually switched off as child mortality fell, incomes rose, women entered the labor force, and state pensions replaced the family as the main source of security in old age. What survived was the second strand: the veneration of education and of status won through examination success, rooted in the imperial examination tradition. Under modern conditions this surviving strand reverses sign with respect to its effect on fertility. Where the historical examination system rewarded having many sons so that one might succeed, the modern single-ranking tournament rewards concentrating resources on one or two intensively educated children, and the quantity–quality tradeoff turns a once pro-natal culture into a powerful engine of low fertility. Drawing on recent empirical evidence from China and Korea, we show how education competition becomes the channel through which traditional values now suppress childbearing. We explain why standard pro-natalist policies, such as removing birth restrictions or offering cash subsidies, accomplish little when the underlying problem is a competitive equilibrium in parental investment, and we argue that policies aimed at the source of the distortion, such as structural reform of educational pathways, hold more promise. |
| JEL: | J1 J10 J13 J18 |
| Date: | 2026–07 |
| URL: | https://d.repec.org/n?u=RePEc:nbr:nberwo:35532 |
| By: | Riccardo Caruso |
| Abstract: | Bitcoin inverse options, traded on the Deribit exchange and settled in the underlying cryptocurrency rather than in fiat currency, combine extreme and genuinely rough volatility dynamics with a non-linear, currency-dependent payoff structure. This paper develops and empirically validates a pricing and calibration framework for these instruments based on the rough Bergomi (rBergomi) model of Bayer, Friz and Gatheral (2016). We adapt the rBergomi dynamics to the inverse payoff max(S_T - K, 0)/S_T, and implement and compare three computational pipelines that differ in the simulation scheme for the driving fractional Brownian motion (coarse-grid Cholesky vs. the Hybrid Scheme of Bennedsen et al., 2017) and in the Monte Carlo pricing estimator (plain log-Euler vs. the Mixed Estimator of McCrickerd and Pakkanen, 2018). The model is calibrated to thirty implied volatility surfaces extracted from Deribit trade data between May 2022 and March 2025, spanning seven major market-stress events and nine baseline regimes stratified by volatility level. The Hybrid and Mixed pipeline is simultaneously the most accurate (mean unweighted RMSE 22.83 percentage points, versus 41.76 pp for the Cholesky and Euler benchmark) and the fastest (17 seconds per snapshot, a 20-fold speed-up). The calibrated Hurst exponent is consistently close to the lower bound of the search space (H approximately equal to 0.01--0.06 in most regimes), confirming that Bitcoin's volatility is genuinely rough, and calibration error scales approximately linearly with the level of at-the-money implied volatility (Pearson r = 0.89). |
| Date: | 2026–08 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2608.27575 |
| By: | Ruichen Deng; Yichi Zhang |
| Abstract: | Lead-lag relationships are widely used in financial time series, and many clustering algorithms based on them have been developed. The traditional DTW-KMedoids algorithm performs well both on the synthetic dataset and the real financial dataset. However, there are still several limitations to these algorithms: low efficiency caused by high time complexity, poor mathematical properties from DTW distance, the clustering effect is sensitive to the number of clusters. To solve the problems above and improve the performance, this paper introduces three clustering algorithms: MiniRocket-KMeans, KShape, Ensemble algorithm (a combination of KShape and DTW-KMedoids) and compares their performance on synthetic and real stock datasets with DTW-KMedoids algorithm under the same trade strategy. In addition, this paper also finds the best number of clusters by maximizing the silhouette coefficient in each clustering algorithm to improve the stability of the experiment results. Our main conclusions are as follows: MiniRocket-KMeans performs best under the lead strategy, achieving a Sharpe ratio of 0.866 with a maximum drawdown controlled at -63.9\%; the ensemble algorithm exhibits excellent stability; the robustness is significantly improved after finding the best number of clusters; the p-values of the hypothesis test on the Sharpe ratio of all strategies are 0.0, verifying the statistical validity of the lead-lag trading strategy. Finally, future improvement directions such as customized lead-lag matrices and optimized ensemble voting mechanisms are proposed. |
| Date: | 2026–08 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2608.24703 |
| By: | Jorrit Gosens; Alex B. H. Turnbull; Frank Jotzo |
| Abstract: | There is renewed attention for maritime chokepoints and their potential disruption of global trade in energy. We analyse global trade in coal, and find that it is highly resilient to maritime chokepoints. Feasible chokepoints do not truly sever any supply from the seaborne market. Potential re-routing of trade flows, and switching to alternative suppliers or consumers moderates effects on costs and revenues. We assess costs to importers would rise by as little as 0.5 \$/t or less in case of closures of most feasible chokepoints. The exception is a restriction to maritime traffic in the South and East China Sea, which could raise costs by 10 \$/t for China, whilst reducing costs for other importers in the region by similar levels. Maritime chokepoints do create geographical separation of regional markets, and therefore do not have a globally uniform effect on costs to importers and revenues to exporters. |
| Date: | 2026–07 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2608.00328 |
| By: | Justus Holman (Vrije Universiteit Amsterdam); Yicong Lin (Vrije Universiteit Amsterdam); Andre Lucas (Vrije Universiteit Amsterdam); Anne Opschoor (Vrije Universiteit Amsterdam) |
| Abstract: | We introduce the Dynamic Spectral Rotation (DSR) model, allowing for dynamics in both eigenvalues and eigenvectors of time-varying conditional covariance matrices. The construction preserves orthonormality of the entire eigenvector matrix at every point in time. We study the model’s asymptotic properties and establish unique identification of all static parameters governing the joint dynamics of eigenvalues and eigenvectors. Notably, the parameters that determine the dynamic rotation angles remain uniquely identified under mild conditions even when the rotation angles are allowed to evolve over ranges far beyond intervals of length π. In an empirical application to US equity returns, we show that allowing the leading eigendirection of the covariance matrix to vary over time significantly improves the predicted portfolio covariance structure compared to a model in which all eigendirections are held fixed. |
| JEL: | C32 C53 C58 |
| Date: | 2026–08–28 |
| URL: | https://d.repec.org/n?u=RePEc:tin:wpaper:20260060 |
| By: | Andrea Vismara; Rafael Prieto-Curiel; Rosie Hayward |
| Abstract: | In 2025, bilateral foreign aid was reduced by 23%, affecting more than 130 aid recipient countries. We assess whether debt service relief or remittance increases can match the USD 26 billion in aid losses. Using a network-shock model calibrated to bilateral donors' individual cuts, we estimate recipient-country aid losses and evaluate compensation feasibility in terms of annual debt service payments that would need to be cancelled and remittance capacity (the headroom between flows and a theoretical maximum in which every working-age migrant sends funds) mobilised to financially offset them. We find that 18% external debt service relief and 10% of remittance mobilisation could compensate half of the affected countries. However, some countries remain locked out of either or both mechanisms. A fundamental trade-off in the global financial architecture emerged for large aid-cut losers: countries positioned to benefit from debt service relief lack large international diaspora networks (limiting their capacity to increase remittances), while those with established diaspora channels face structural exclusion of traditional debt markets, rendering debt service relief ineffective. These insights introduce nuance in how alternative finance sources can replace foreign aid. |
| Date: | 2026–08 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2608.21843 |
| By: | Fetzer, Thiemo; Lambert, Peter John |
| Abstract: | Policy debates on ‘critical minerals’ have multiplied faster than our empirical tools for identifying which products are system-critical. Most existing lists are expert-driven and static; they say little about how upstream raw materials and downstream technologies are knit together in global production networks, or about the asymmetric roles of large demand and supply hubs. This paper proposes a network index of criticality (NIC), built from trade data and a directed production network, that integrates (i) a product’s share in world trade, (ii) exporter and importer concentration, and (iii) its position in a product-input network. Criticality here refers to systemic exposure encoded in tradeable production networks; it is not a welfare metric and it is not a measure of physical scarcity. We show that NIC aligns with revealed policy attention in official critical-mineral lists. We then construct three families of counterfactuals that remove China, the United States, or the European Union from trade on either the export (supply) or import (demand) side. These scenarios yield product-level diagnostics of hub dependence and map directly to policy instrument choice (e.g. recycling standards, permitting and processing investment, strategic reserves, or trusted-partner agreements). |
| Keywords: | climate action;critical minerals;industrial policy;production networks;supply chain resilience;trade concentration |
| JEL: | F10 F40 F50 O30 L60 Q40 Q50 |
| Date: | 2026–08–04 |
| URL: | https://d.repec.org/n?u=RePEc:ehl:lserod:140668 |
| By: | Timothy Besley; Peter John Lambert; Isabelle Michalski-Roland; John Van Reenen |
| Abstract: | This paper examines the impact of credit frictions arising from firm-level default risk on aggregate economic performance. We build a micro-to-macro model with heterogeneous firms and sector-specific production functions, showing that perceived default risk is a sufficient statistic for credit frictions. Using UK administrative data (2004-2019) matched to S&P risk measures, counterfactual estimates reveal that relaxing frictions raises output by 25% and wages by 23%. Ignoring equilibrium wage adjustments overstates output gains, while fixed-capital misallocation approaches understate them. Most gains reflect aggregate capital accumulation. Credit frictions remain above pre-crisis levels, reshape firm size dynamics, increase misallocation across firms, and dampen productivity growth over time. |
| Keywords: | productivity, default risk, credit frictions, misallocation |
| Date: | 2026–07–29 |
| URL: | https://d.repec.org/n?u=RePEc:cep:cepdps:dp2201 |
| By: | Haberlah, Johannes; Linke, Knut |
| Abstract: | This discussion paper compares three common serialization paradigms - JSON, Protocol Buffers, and FlatBuffers - with respect to latency and space efficiency. Although serialization is central to modern distributed systems, controlled, paradigm-level comparisons remain limited. To address this, the study benchmarks all three formats in Rust while systematically varying record width and nesting depth. Quantitative measurements are complemented by CPU profiling to identify dominant cost drivers. Results show clear patterns: Protocol Buffers achieves the lowest serialization latency and smallest message sizes, FlatBuffers offers the fastest data access due to its zero-copy design, and JSON incurs the highest access costs and largest payloads. Each format therefore excels under different conditions: Protobuf in write-and bandwidth-sensitive scenarios, FlatBuffers in read-dominated contexts, and JSON where readability and flexibility matter. |
| Keywords: | Serialization, Protocol Buffers, FlatBuffers, Zero-copy, Benchmarking |
| JEL: | C80 C88 L86 |
| Date: | 2026 |
| URL: | https://d.repec.org/n?u=RePEc:zbw:iubhit:343093 |