Hasil untuk "Trade associations"

Demetrio Lacava

This paper examines how trade policy uncertainty influences the correlation between U.S. stock indices and short-term government bonds. The objective is to assess whether policy-related shocks, especially those linked to trade tensions, alter the traditional stock-T bill relationship and its implications for investors. We extend the Dynamic Conditional Correlation (DCC) framework by incorporating exogenous variables to account for external shocks. Three specifications are analyzed: one using the Trade Policy Uncertainty (TPU) index, one including a dummy variable reflecting presidential-cycle effects, and one combining both through an interaction term. The analysis is based on daily data for major U.S. stock indices and the 3-month Treasury bill. Results indicate that trade policy uncertainty exerts a significant effect on stock-T bill correlations. Moreover, its influence becomes stronger under specific political conditions, suggesting that political agendas can amplify the impact of trade-related shocks on financial markets. Crucially, augmenting the DCC framework with trade-policy-related variables improves also the economic relevance of correlation forecasts. Therefore, this study contributes to the literature by explicitly integrating policy-related uncertainty into correlation modeling through an augmented DCC framework. The findings provide new insights for portfolio allocation and risk management in environments characterized by heightened trade tensions.

Elias Aravantinos

This study introduces the Digital Competitiveness Index for Trade (DCIT), a composite metric integrating ICT readiness, broadband adoption, GDP per capita, foreign direct investment, government effectiveness, and trade volume to assess countries' digital trade competitiveness. The index captures the enabling conditions -- ICT innovation capacity, broadband diffusion, investment intensity, and macroeconomic fundamentals - that shape a nation's ability to participate in digital trade. Sensitivity analysis demonstrates strong robustness: adjusting ICT-FDI weights alters DCIT outcomes by only 26%, with near perfect linearity (R^2 = 0.9996). Predictive validation shows that DCIT is a strong explainer of trade connectivity growth (R^2 = 0.67) but a modest predictor of GDP expansion. Scenario simulations reveal that combined ICT and FDI acceleration consistently outperforms single-lever strategies, with gains increasing by cluster maturity (up to 10% in advanced clusters). High-growth scenarios generate a 50-60% uplift in competitiveness for mid-tier and advanced clusters, underscoring the importance of integrated digital investment strategies.

Jason Hartline, Kangning Wang

We provide a geometric proof that the random proposer mechanism is a $4$-approximation to the first-best gains from trade in bilateral exchange. We then refine this geometric analysis to recover the state-of-the-art approximation ratio of $3.15$.

Muhammad Sukri Bin Ramli

The global trade in electronic and electrical goods is complicated by the challenge of identifying e-waste, which is often misclassified to evade regulations. Traditional analysis methods struggle to discern the underlying patterns of this illicit trade within vast datasets. This research proposes and validates a robust, data-driven framework to segment products and identify goods exhibiting an anomalous "waste signature" a trade pattern defined by a clear 'inverse price-volume'. The core of the framework is an Outlier-Aware Segmentation method, an iterative K-Means approach that first isolates extreme outliers to prevent data skewing and then re-clusters the remaining products to reveal subtle market segments. To quantify risk, a "Waste Score" is developed using a Logistic Regression model that identifies products whose trade signatures are statistically similar to scrap. The findings reveal a consistent four-tier market hierarchy in both Malaysian and global datasets. A key pattern emerged from a comparative analysis: Malaysia's market structure is defined by high-volume bulk commodities, whereas the global market is shaped by high-value capital goods, indicating a unique national specialization. The framework successfully flags finished goods, such as electric generators (HS 8502), that are traded like scrap, providing a targeted list for regulatory scrutiny.

Youlei Shen, Xuesi Zhu, Tingyu Duan

The pea aphid (Acyrthosiphon pisum), a significant insect pest characterized by its piercing-sucking feeding pattern, severely impairs plant growth and productivity, leading to substantial economic losses. While arbuscular mycorrhizal fungus (AMF) and Epichloë endophyte is associated with enhancing host plant resistance to insect infestations, research on their dual colonization and its impact on insect infestation remains limited. Our study investigated the effects of co-colonization of AMF Rhizophagus intraradices, and Epichloë festucae var. lolii endophyte on ryegrass response to aphid infestation. We quantified nutrient allocation dynamics, symbiotic efficiency, and defense-related enzyme activities to elucidate physiological trade-offs between growth maintenance and anti-herbivore defense strategies under dual symbiont colonization. Our findings revealed that aphid infestation significantly reduced plant growth, shoot phosphorus (P) and nitrogen (N) contents, and mycorrhizal P responsiveness. However, co-colonization by AMF and Epichloë endophyte effectively reversed these negative effects. There are significant interactions among AMF, Epichloë endophyte and aphids, E. festucae var. lolii alone reduced mycorrhizal colonization, while aphid infestation notably increased it. Interestingly, the combined presence of aphid infestation and E. festucae var. lolii led to the highest AMF colonization levels in Lolium perenne. Both R. intraradices and Epichloë endophyte, whether individually or in combination, effectively mitigated aphid feeding damage. Tripartite interactions among R. intraradices, Epichloë endophytes, and A. pisum significantly affected chitinase activity. Furthermore, the combined presence of R. intraradices and E. festucae var. lolii augmented superoxide dismutase and β-1,3-glucanase activities under aphid attack. Our results offer insights into the complex symbiotic relationships between plants, symbiotic fungi, and herbivores, underscoring the potential of AMF-Epichloë associations to bolster anti-herbivore defenses.

Wenning Sun, Shilong Zhang, Xingli Ma et al.

BackgroundHainan is a pilot free trade port in China and a multiethnic province. Catastrophic health expenditure (CHE) reflects health care inequity, particularly affecting vulnerable groups in rapidly developing multiethnic regions. ObjectiveThis study aims to analyze CHE prevalence and intensity and their influencing factors among residents in a Chinese multiethnic province. MethodsData from the 2023 Hainan Province Health Services Survey, conducted among 14,532 individuals aged 18 years or older, were used in a multistage stratified cluster sampling. CHE was defined as out-of-pocket health care payments exceeding 40% of the household’s capacity to pay. The chi-square test and a logistic regression were used to identify influencing factors for CHE. Nonparametric tests and quantile regression were used to evaluate the influencing factors for CHE intensity. ResultsThe prevalence of CHE in Hainan province was 8.37%, with a median intensity of 17.67% (IQR 8.31%-29.77%). Residents were more likely to experience CHE if they were older than 60 years (odds ratio [OR] 1.928, 95% CI 1.602-2.320; P<.001), unmarried (OR 1.241, 95% CI 1.075-1.433; P=.003), or had chronic illnesses (OR 2.214, 95% CI 1.930-2.540; P<.001). Ethnic minority groups (OR 0.774, 95% CI 0.679-0.883; P<.001) as well as middle-income (OR 0.722, 95% CI 0.600-0.869; P=.001), high-middle-income (OR 0.739; 95% CI 0.609-0.898; P=.002), and high-income (OR 0.591, 95% CI 0.474-0.738; P<.001) groups were less likely to experience CHE. At lower CHE intensity (20th percentile), individuals older than 60 years (β=1.935; P=.03) and middle-income (β=1.737; P=.04) and rural (β=2.202; P=.005) residents showed positive associations. At the 50th percentile, low-middle-income (β=–5.052; P=.005), high-middle-income (β=–4.203; P=.03), and high-income (β=–6.534; P=.004) groups showed negative associations. At the 80th percentile, high-middle-income (β=–7.143; P=.03) and rural (β=–6.241; P=.005) groups showed stronger financial protection. ConclusionsAddressing CHE risks remains a critical challenge in Hainan province, highlighting structural inequities rooted in socioeconomic disparities and health vulnerabilities. Therefore, policy should prioritize primary prevention in the lowest-income populations while implementing enhanced insurance coverage for rural populations facing extreme costs to alleviate the most severe financial burdens.

Yu Kang, Ge Wang, Xin Yang et al.

The development of Large Language Models (LLMs) has created transformative opportunities for the financial industry, especially in the area of financial trading. However, how to integrate LLMs with trading systems has become a challenge. To address this problem, we propose an intelligent trade order recognition pipeline that enables the conversion of trade orders into a standard format in trade execution. The system improves the ability of human traders to interact with trading platforms while addressing the problem of misinformation acquisition in trade execution. In addition, we have created a trade order dataset of 500 pieces of data to simulate real-world trading scenarios. Moreover, we designed several metrics to provide a comprehensive assessment of dataset reliability and the generative power of big models in finance by experimenting with five state-of-the-art LLMs on our dataset. The results indicate that while LLMs demonstrate high generation rates (87.50% to 98.33%) and perfect follow-up rates, they face significant challenges in accuracy (5% to 10%) and completeness, with high missing rates (14.29% to 67.29%). In addition, LLMs tend to over-interrogate, suggesting that large models tend to collect more information, carrying certain challenges for information security.

Durgesh Nandini, Simon Bloethner, Mirco Schoenfeld et al.

Understanding the complex dynamics of high-dimensional, contingent, and strongly nonlinear economic data, often shaped by multiplicative processes, poses significant challenges for traditional regression methods as such methods offer limited capacity to capture the structural changes they feature. To address this, we propose leveraging the potential of knowledge graph embeddings for economic trade data, in particular, to predict international trade relationships. We implement KonecoKG, a knowledge graph representation of economic trade data with multidimensional relationships using SDM-RDFizer, and transform the relationships into a knowledge graph embedding using AmpliGraph.

Indre Treciokiene, Kamile Daukintyte, Paul Hjemdahl et al.

Aims: To compare statin utilization and ischemic heart disease (IHD) mortality trends in Lithuania and Sweden and to assess correlations between the total utilization of statins and IHD mortality. Methods: An ecological study assessing time trends in statin utilization (DDDs per 1000 inhabitants per day; DDD/TID) and IHD mortality in Lithuania and Sweden between 2000 and 2020. Statin utilization data in Lithuania were wholesale trade data, and Swedish data were drugs dispensed at pharmacies. IHD mortality data were extracted from national databases as rates per 100 000 inhabitants. Associations between statin utilization and IHD mortality in Lithuania and Sweden were examined using Spearman’s rank and Pearson’s correlation coefficients, respectively. Results: Statin utilization increased from 16.8 to 135.8 DDD/TID in Sweden and from 0.2 to 61.8 DDD/TID in Lithuania between 2000 and 2020. Medium intensity was the most common statin dosage in Lithuania, while Sweden used more high intensity than moderate-intensity statins from 2017. IHD mortality in Lithuania remained high between 2000 and 2020 (from 359.1 to 508.8 deaths per 100 000 population), while it decreased markedly in Sweden (from 226.87 to 88.7 deaths per 100 000 population). IHD mortality and statin utilization were inversely correlated in Sweden (r = -0.993, P < 0.001), while a positive correlation was found in Lithuania (rs = 0.871, P < 0.001). Conclusion: Despite the growing statin utilization in both countries, Lithuania recorded a slight increase in IHD mortality rates unlike the situation in Sweden. This indicates room for improvement in the management of modifiable cardiovascular risk factors in Lithuania including how statins are prescribed and used in clinical practice.

Xiaowei Yang, Huiling Yan, Chunhui Hao et al.

Abstract Background Variations in hydraulic conductivity may arise from species-specific differences in the anatomical structure and function of the xylem, reflecting a spectrum of plant strategies along a slow-fast resource economy continuum. Spruce (Picea spp.), a widely distributed and highly adaptable tree species, is crucial in preventing soil erosion and enabling climate regulation. However, a comprehensive understanding of the variability in anatomical traits of stems and their underlying drivers in the Picea genus is currently lacking especially in a common garden. Results We assessed 19 stem economic properties and hydraulic characteristics of 17 Picea species grown in a common garden in Tianshui, Gansu Province, China. Significant interspecific differences in growth and anatomical characteristics were observed among the species. Specifically, xylem hydraulic conductivity (K s) and hydraulic diameter exhibited a significant negative correlation with the thickness to span ratio (TSR), cell wall ratio, and tracheid density and a significant positive correlation with fiber length, and size of the radial tracheid. PCA revealed that the first two axes accounted for 64.40% of the variance, with PC1 reflecting the trade-off between hydraulic efficiency and mechanical support and PC2 representing the trade-off between high embolism resistance and strong pit flexibility. Regression analysis and structural equation modelling further confirmed that tracheid size positively influenced K s, whereas the traits DWT, D_r, and TSR have influenced K s indirectly. All traits failed to show significant phylogenetic associations. Pearson’s correlation analysis demonstrated strong correlations between most traits and longitude, with the notable influence of the mean temperature during the driest quarter, annual precipitation, precipitation during the wettest quarter, and aridity index. Conclusions Our results showed that xylem anatomical traits demonstrated considerable variability across phylogenies, consistent with the pattern of parallel sympatric radiation evolution and global diversity in spruce. By integrating the anatomical structure of the stem xylem as well as environmental factors of origin and evolutionary relationships, our findings provide novel insights into the ecological adaptations of the Picea genus.

Robin E. Klabbers, Canada Parrish, Patient Iraguha et al.

Background: A better understanding of refugee mobility is needed to optimize HIV care in refugee settlements. Objectives: We aimed to characterize mobility patterns among people living with HIV in refugee settlements in Uganda and evaluate the association between mobility and retention in HIV care. Methods: Refugees and Ugandan nationals accessing HIV services at seven health centers in refugee settlements across Uganda, with access to a phone, were recruited and followed for six months. Participants received an intake survey and monthly phone surveys on mobility and HIV. Clinic visit and viral suppression data were extracted from clinic registers. Mobility and HIV data were presented descriptively, and an alluvial plot was generated characterizing mobility for participants’ most recent trip. Bivariate Poisson regression models were used to describe the associations between long-term mobility (≥1 continuous month away in the past year) and demographic characteristics, retention (≥1 clinic visit/6 months) and long-term mobility, and retention and general mobility (during any follow-up month: ≥2 trips, travel outside the district or further, or spending >1–2 weeks (8–14 nights) away). Findings: Mobility data were provided by 479 participants. At baseline, 67 participants (14%) were considered long-term mobile. Male sex was associated with an increased probability of long-term mobility (RR 2.02; 95%CI: 1.30–3.14, p < 0.01). In follow-up, 185 participants (60% of respondents) were considered generally mobile. Reasons for travel included obtaining food or supporting farming activities (45% of trips) and work or trade (33% of trips). Retention in HIV care was found for 417 (87%) participants. Long-term mobility was associated with a 14% (RR 0.86; 95%CI: 0.75–0.98) lower likelihood of retention (p = 0.03). Conclusions: Refugees and Ugandan nationals accessing HIV care in refugee settlements frequently travel to support their survival needs. Mobility is associated with inferior retention and should be considered in interventions to optimize HIV care.

Satoshi Nakano, Kazuhiko Nishimura

This paper is about our attempt of identifying trade elasticities through the variations in the exchange rate, for possible applications to the case of services whose physical transactions are veiled in the trade statistics. The regression analysis to estimate the elasticity entails a situation where the explanatory variable is leaked into the error term through the latent supply equation, causing an endogeneity problem for which an instrumental variable cannot be found. Our identification strategy is to utilize the normalizing condition, which enables the supply parameter to be identified, along with the reduced-form equation of the system of demand and supply equations. We evaluate the performances of the method proposed by applying to several different tangible goods, whose benchmark trade elasticities are estimable by utilizing the information on their physical transactions.

Muhammad Shafiq Shahid, Jorge R. Paredes-Montero, Muhammad Ashfaq et al.

Irrigated agriculture and global trade expansion have facilitated diversification and spread of begomoviruses (<i>Geminiviridae</i>), transmitted by the <i>Bemisia tabaci</i> (Gennadius) cryptic species. Oman is situated on major crossroads between Africa and South Asia, where endemic/native and introduced/exotic begomoviruses occur in agroecosystems. The <i>B. tabaci</i> ‘B mitotype’ belongs to the North Africa–Middle East (NAFME) cryptic species, comprising at least eight endemic haplotypes, of which haplotypes 6 and/or 8 are recognized invasives. Prevalence and associations among native and exotic begomoviruses and NAFME haplotypes in Oman were investigated. Nine begomoviral species were identified from <i>B. tabaci</i> infesting crop or wild plant species, with 67% and 33% representing native and exotic species, respectively. Haplotypes 2, 3, and 5 represented 31%, 3%, and 66% of the <i>B. tabaci</i> population, respectively. Logistic regression and correspondence analyses predicted ‘strong’- and ‘close’ virus–vector associations involving haplotypes 5 and 2 and the exotic chili leaf curl virus (ChiLCV) and endemic tomato yellow leaf curl virus-OM, respectively. Patterns favor a hypothesis of relaxed virus–vector specificity between an endemic haplotype and the introduced ChiLCV, whereas the endemic co-evolved TYLCV-OM and haplotype 2 virus–vector relationship was reinforced. Thus, in Oman, at least one native haplotype can facilitate the spread of endemic and introduced begomoviruses.

Parker JL, Vakulin A, Melaku YA et al.

Jesse L Parker,1 Andrew Vakulin,1,2 Yohannes Adama Melaku,1 Gary A Wittert,3,4 Sean A Martin,3,4 Angela L D’Rozario,2,5 Peter G Catcheside,1 Bastien Lechat,1 Barbara Toson,6 Alison J Teare,1 Sarah L Appleton,1,4,&ast; Robert J Adams1,4,7,&ast; 1Flinders Health and Medical Research Institute, Adelaide Institute for Sleep Health, Flinders University, Adelaide, SA, Australia; 2CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia; 3Freemasons Centre for Male Health and Wellbeing, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia; 4South Australian Health and Medical Research Institute, Adelaide, SA, Australia; 5The University of Sydney, Faculty of Science, School of Psychology, Sydney, NSW, Australia; 6College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia; 7Respiratory and Sleep Services, Southern Adelaide Local Health Network, Adelaide, SA, Australia&ast;These authors contributed equally to this workCorrespondence: Jesse L Parker, Flinders Health and Medical Research Institute, Adelaide Institute for Sleep Health, Mark Oliphant Building, Flinders University, 5 Laffer Drive, Bedford Park, Adelaide, SA, 5042, Australia, Tel +61 0420431392, Email park0769@flinders.edu.auPurpose: Prospective studies examining associations between baseline sleep microarchitecture and future cognitive function recruited from small samples with predominantly short follow-up. This study examined sleep microarchitecture predictors of cognitive function (visual attention, processing speed, and executive function) after 8 years in community-dwelling men.Patients and Methods: Florey Adelaide Male Ageing Study participants (n=477) underwent home-based polysomnography (2010– 2011), with 157 completing baseline (2007– 2010) and follow-up (2018– 2019) cognitive assessments (trail-making tests A [TMT-A] and B [TMT-B] and the standardized mini-mental state examination [SMMSE]). Whole-night F4-M1 sleep EEG recordings were processed following artifact exclusion, and quantitative EEG characteristics were obtained using validated algorithms. Associations between baseline sleep microarchitecture and future cognitive function (visual attention, processing speed, and executive function) were examined using linear regression models adjusted for baseline obstructive sleep apnoea, other risk factors, and cognition.Results: The final sample included men aged (mean [SD]) 58.9 (8.9) years at baseline, overweight (BMI 28.5 [4.2] kg/m2), and well educated (75.2% ≥Bachelor, Certificate, or Trade), with majorly normal baseline cognition. Median (IQR) follow-up was 8.3 (7.9, 8.6) years. In adjusted analyses, NREM and REM sleep EEG spectral power was not associated with TMT-A, TMT-B, or SMMSE performance (all p> 0.05). A significant association of higher N3 sleep fast spindle density with worse TMT-B performance (B=1.06, 95% CI [0.13, 2.00], p=0.026) did not persist following adjustment for baseline TMT-B performance.Conclusion: In this sample of community-dwelling men, sleep microarchitecture was not independently associated with visual attention, processing speed, or executive function after 8 years.Keywords: quantitative EEG, spindles, attention, processing speed, executive function

Orhan Karaoğlu

The phenomenon of religion appears as a multidimensional element in terms of individual, society and state. It has effects on people individually as well as in the context of social and international relations. In terms of states, religion appears as a phenomenon that affects and determines the domestic and foreign policies of states. Especially in the 21st century, we see that religion has begun to affect international relations in various areas. Another area where International Relations has begun to establish relations in recent years has been religion. Especially when foreign policy decision-making processes are examined, it is seen that religious beliefs, religion-based organizations and non-governmental organizations are effective in the decision-making processes of state administrators. The issue of Islamic Sects, and Shi’ism in particular, has been a much-discussed phenomenon in recent years due to its global and regional effects. Along with the Persian perspective inherited from the Persian Empire, Shi'ism has significantly influenced and continues to influence the geopolitical and geocultural education of today's Iran. With its politicization, Shiism has become one of the factors that play an important role in the creation and preservation of Iran's national identity, perhaps the most important. In this context, Iranian Shiism, which creates a socio-cultural system different from other civilizations around it, has become the main determinant on the security and foreign policy of today's Iran by intertwining with Persian nationalism since the reign of Shah Ismail. Iran has influenced Shiite communities in various regions - the Middle East, Africa - Central Asia - through its Shiite proxies, or has worked to Shiite the promising masses in the political field. Iran also has an influence on Shiite Muslims in Europe. Its relationship with the Shiite communities here appears as an important element in Iran's relations with European countries in the context of foreign policy. Shiite activities in Germany are carried out through an association in Hamburg, where Iranian business people have been living for many years. The Islamic Center of Hamburg describes itself as the "case representative" of the Shiites in Europe, especially in Germany. The concentration of Shiites and organizations in Germany in a single center is entirely in line with Iran's aim of "uniting the Shiites of the world under its rule and spreading Shiism (the belief in velayat-e faqih) from a single center". Approximately 200,000 Shiites live in France. Ten associations and cultural centers, which have been identified as carrying out religious activities on the basis of Shiism, are active in the country on behalf of Iran. Shiites currently constitute 10% of the total number of Muslims in the UK. Persian community centers have been established in the UK since the 1980s. Iranian individuals have established associations in the UK in many fields such as trade, health, culture and religion. It is estimated that these associations aim to spread Shiism among Muslim communities in the UK. Iran is trying to be active in Europe through these groups and Shiism is an important element in its relations with Europe.

Pratik Rajan Gupte, Gregory F Albery, Jakob Gismann et al.

Animal sociality emerges from individual decisions on how to balance the costs and benefits of being sociable. Novel pathogens introduced into wildlife populations should increase the costs of sociality, selecting against gregariousness. Using an individual-based model that captures essential features of pathogen transmission among social hosts, we show how novel pathogen introduction provokes the rapid evolutionary emergence and coexistence of distinct social movement strategies. These strategies differ in how they trade the benefits of social information against the risk of infection. Overall, pathogen-risk-adapted populations move more and have fewer associations with other individuals than their pathogen-risk-naive ancestors, reducing disease spread. Host evolution to be less social can be sufficient to cause a pathogen to be eliminated from a population, which is followed by a rapid recovery in social tendency. Our conceptual model is broadly applicable to a wide range of potential host–pathogen introductions and offers initial predictions for the eco-evolutionary consequences of wildlife pathogen spillover scenarios and a template for the development of theory in the ecology and evolution of animals’ movement decisions.

G.G. Bodurova

This article deals with the problem of defining the legal nature of integration associations, mainly regional, as well as with the issue of revealing their major role in world affairs. Notably, it is possible to clarify the legal essence of these entities if their individual features distinguishing integration associations from the existing form of interstate cooperation, in particular international organizations, are known. Of special interest are the characteristics of such regional integration associations that are based on larger associations, such as the Eurasian Economic Union, a trade agreement between several post-Soviet states, and the European Union, a political and economic association of European states. The relations of an international character developing during the interstate cooperation within the framework of regional integration associations were described with the help of the comparative and analytical methods. A comprehensive legal definition of the concept of regional integration associations was provided based on their unique features. The latter were analyzed in detail. The considered forms of interstate cooperation were compared with international organizations. The results obtained show that an integration association is a special form of interstate cooperation of a regional nature, which is aimed at the development of foreign economic relations between member states.

Justin Loye, Katia Jaffrès-Runser, Dima Shepelyansky

We develop the Google matrix analysis of the multiproduct world trade network obtained from the UN COMTRADE database in recent years. The comparison is done between this new approach and the usual Import-Export description of this world trade network. The Google matrix analysis takes into account the multiplicity of trade transactions thus highlighting in a better way the world influence of specific countries and products. It shows that after Brexit, the European Union of 27 countries has the leading position in the world trade network ranking, being ahead of USA and China. Our approach determines also a sensitivity of trade country balance to specific products showing the dominant role of machinery and mineral fuels in multiproduct exchanges. It also underlines the growing influence of Asian countries.

Matthieu Nadini, Alberto Bracci, Abeer ElBahrawy et al.

Dark web marketplaces (DWMs) are online platforms that facilitate illicit trade among millions of users generating billions of dollars in annual revenue. Recently, two interview-based studies have suggested that DWMs may also promote the emergence of direct user-to-user (U2U) trading relationships. Here, we quantify the scale of, and thoroughly investigate, U2U trading around DWMs by analysing 31 million Bitcoin transactions among users of 40 DWMs between June 2011 and Jan 2021. We find that half of the DWM users trade through U2U pairs generating a total trading volume greater than DWMs themselves. We then show that hundreds of thousands of DWM users form stable trading pairs that are persistent over time. Users in stable pairs are typically the ones with the largest trading volume on DWMs. Then, we show that new U2U pairs often form while both users are active on the same DWM, suggesting the marketplace may serve as a catalyst for new direct trading relationships. Finally, we reveal that stable U2U pairs tend to survive DWM closures and that they were not affected by COVID-19, indicating that their trading activity is resilient to external shocks. Our work unveils sophisticated patterns of trade emerging in the dark web and highlights the importance of investigating user behaviour beyond the immediate buyer-seller network on a single marketplace.

Matthew H. Holden, Jakeb Lockyer

Can a regulated, legal market for wildlife products protect species threatened by poaching? It is one of the most controversial ideas in biodiversity conservation. Perhaps the most convincing reason for legalizing wildlife trade is that trade revenue could fund the protection and conservation of poached species. In this paper, we examine the possible poacher-population dynamic consequences of legal trade funding conservation. The model consists of a manager scavenging carcasses for wildlife products, who then sells the products, and directs a portion of the revenue towards funding anti-poaching law enforcement. Through a global analysis of the model, we derive the critical proportion of product the manager must scavenge, and the critical proportion of trade revenue the manager must allocate towards increased enforcement, in order for legal trade to lead to abundant long-term wildlife populations. We illustrate how the model could inform management with parameter values derived from the African elephant literature, under a hypothetical scenario where a manager scavenges elephant carcasses to sell ivory. We find that there is a large region of parameter space where populations go extinct under legal trade, unless a significant portion of trade revenue is directed towards protecting populations from poaching. The model is general and therefore can be used as a starting point for exploring the consequences of funding many conservation programs using wildlife trade revenue.