Time-varying Analysis Research Articles

Stablecoins and emerging market currencies: a time-varying analysis

PurposeOwing to the growing evidence of crypto asset connectedness and correlation with traditional financial assets, this study sought to determine if there is a time-varying correlation and/or connectedness between the stablecoin market and the currencies of emerging market and developing economies (EMDEs) with significant cryptocurrency penetration.Design/methodology/approachThis study uses a probabilistic principal component analysis (PPCA) to create stablecoin and EMDEs currency returns and volatility indices for EMDEs with significant cryptocurrency penetration. We then employ a time-varying correlation and time-varying parameter vector autoregressive (TVP-VAR) connectedness measures to document the time-dependent correlation and connectedness between the EMDE currencies and the stablecoin market.FindingsThe result points to a spillover of return shocks from the EMDE currencies to the stablecoin market prior to and after the COVID-19 pandemic. This is indicative of a flight-to-safety role of stablecoins for EMDE currencies. This calls for increased attention to the stablecoin market by money market investors and monetary authorities.Originality/valueThe paper contributes to the growing cryptocurrency and finance literature by empirically examining the level of connectedness between stablecoins and emerging market currencies. Knowing the relationship (correlation) and shock spillover (connectedness) between the stablecoins and the EMDE currencies will be valuable to currency investors’ diversification and hedging strategies, and to macroeconomic policymakers in designing and implementing regulation.

Electrophysiological activity underlying motor inhibition facilitated by touch.

Tactile sensory information obtained from oneself or others may provide a calming effect and has been shown to enhance participants' motor control. The extent to which these touch activities may support motor inhibition and the related electrophysiological mechanisms remain unknown. Here, we investigated these effects in twenty healthy volunteers via electroencephalography under 3 touching conditions (self-touch, other-touch, and no-touch) during a stop-signal task. We found that both the self-touch and other-touch conditions resulted in better stopping accuracy and lower stop-signal reaction times than the no-touch condition. Additionally, these 2 touch conditions elicited larger N2 and P3 responses during successful inhibition of planned finger movements. Time-varying network analysis based on electroencephalography was further used to explore the differences in brain networks during conflict monitoring substages under different touch conditions. A top-down projection from the frontal cortex (Fz) to the parietal and occipital cortices was observed along with increased functional connectivity efficiency under touch conditions. These results indicate that tactile information may enhance neural processing efficiency in the human brain by eliciting larger event-related potential components and promoting information processing in the brain network during conflict monitoring processes, thereby contributing to the reactive inhibitory component of motor inhibition.

Prenatal exposure to heat and humidity and infant birth size in Ghana.

Previous studies - primarily in high income countries - have shown that high prenatal temperatures are associated with adverse birth outcomes. However, these studies are mostly focused on average exposure across the full gestational period or short-term exposure immediately prior to delivery and may miss important sensitive windows of exposure in utero. Further, nearly all use ambient air temperature data, which neglect physiologically important interactions between air temperature and humidity. The Ghana Randomized Air Pollution and Health Study (GRAPHS) recruited pregnant individuals from 2013 to 2015 from communities in the Kintampo North Municipality and Kintampo South District of Ghana. We estimated daily maximum shaded wet bulb globe temperature (WBGTmax) and heat index (HImax) during pregnancy and examined associations with birth weight, birth length, head circumference, and incidence of low birth weight, preterm birth, and small for gestational age. Using linear regression analyses, trimester average models identified that higher WBGTmax in the first trimester was associated with larger head circumference; second trimester was associated with shorter birth length, lower birth weight and higher odds of preterm birth, and third trimester was associated with shorter gestational age and larger head circumference. Time-varying analyses using distributed lag nonlinear models find that, compared to the median, lower WBGTmax and HImax (25th percentile) during the first half of pregnancy was associated with higher birth weight and longer birth length. Compared to the median, lower WBGTmax and HImax (25th percentile) in the second half of pregnancy was associated with smaller head circumference while higher wet bulb globe temperature (75th percentile) was associated with larger head circumference. Overall, our study identified that higher WBGTmax and HImax are associated with pregnancy duration and newborn size. Given the overall trend in our study area of rising temperatures, these data suggest that adaptation strategies are urgently needed to protect child health.

Care fragmentation in hepatocellular carcinoma: Opportunities to fix a broken sector.

Care fragmentation refers to receipt of health care services through multiple institutions. Although care fragmentation has been linked to inferior oncologic outcomes, it also captures "upgrades" to specialized centers. Herein, we investigate the association between care fragmentation and hepatocellular carcinoma survival in California. Hepatocellular carcinoma cases occurring between January 1, 2007, and December 31, 2017, were retrospectively identified through a maintained, statewide database. Care fragmentation was measured (1) as a binary classification of fragmented or nonfragmented care, (2) by the number of facilities visited, and (3) in terms of care directionality through which care fragmentation occurred between Network of Comprehensive Cancer/National Cancer Institute-designated and -nondesignated centers, within 2years of diagnosis. Multivariable time-varying covariate Cox regression analyses were used to model the impact of care fragmentation on overall survival. Of 10,825 patients with hepatocellular carcinoma, 5,778 patients (53.4%) received fragmented care. Compared with nonfragmented care, fragmented care was associated with worse overall survival (hazard ratio, 1.81; 95% confidence interval, 1.72-1.91, P < .001) by our analyses. The quantity of centers visited also corresponded to a greater mortality (2 facilities: hazard ratio, 1.65; 95% confidence interval, 1.56-1.75, P<.001; 3 facilities: hazard ratio, 2.21; 95% confidence interval, 2.02-2.41, P<.001; 4+ facilities: hazard ratio, 2.66; 95% confidence interval, 2.35-3.02, P<.001). Compared with nonfragmented-designated, all other care fragmentation directionality patterns, including fragmented-designated and nondesignated care, decreased overall survival (hazard ratio, 1.74; 95% confidence interval, 1.55-1.95, P<.001). Care fragmentation in surgical patients showed a similar trend for the fragmented-designated and nondesignated pattern (hazard ratio, 1.67; 95% confidence interval, 1.30-2.14, P<.001). In hepatocellular carcinoma, fragmented care is associated with worse survival. Although fragmented-designated and nondesignated care was expected to mitigate such effect, this was not observed. Additional mechanisms driving such findings warrant further investigation.

In Search of L-Fuzzy Contexts Adaptable to Variable Information: A Tool for Time-Varying Data Analysis

This paper sheds light on the study of a new structure, called L-fuzzy hypercontext, which provides an extension of the range of applications of fuzzy concept analysis. The advantage of working with L-fuzzy hypercontexts lies in the fact that we can establish relation among elements such that their values are, in turn, other relations. Thus, they are easily adaptable to different situations that vary over time. The usefulness of the developed theory is illustrated by a practical case in which the valuation made by the different clients of a hotel company is analyzed.

Dynamic Neural Mechanisms Underlying Sustained Motor Training Post-Stroke: An fNIRS Investigation Employing Time-Varying ALFF and Functional Connectivity Analysis.

Motor dysfunction of the upper limbs following a stroke predominantly arises from abnormal motor patterning caused by the disrupted balance of inter-cortical communication within motor-associated cortical regions. Temporal analysis offers a more precise reflection of the cortical functional state in affected patients. This study employed fNIRS to capture hemodynamic responses among 20 stroke patients and 19 healthy controls in both resting and Baduanjin task state. Including computing the coefficient of variation of fractional amplitude of low-frequency fluctuations (fALFF) for each channel, alongside extracting dynamic state metrics. Findings indicate that, during sustained motor tasks, stroke patients exhibit a diminished fALFF variability in targeted cortical regions; these individuals display a higher prevalence of low-intensity states and a lower prevalence of high-intensity states during task execution. These dynamic state attributes are significantly associated with scores on the upper limb motor function scale (FMA-UE), thereby proposing a time-domain perspective for investigating the underlying mechanisms of stroke-induced motor dysfunction.

A Single-Loop Method for Time-Variant Reliability Sensitivity Analysis of Motion Mechanisms Using Bayes’ Theorem

Abstract Time-variant reliability sensitivity (TRS) analysis can measure the effect of input factors on the structure/mechanism failure. The traditional method for TRS analysis employs a nested sampling procedure, with computational cost depending on the number of input factors. To address the above weaknesses, a single-loop method is developed for TRS analysis. Based on Bayes’ theorem, the sensitivity measure is derived and expressed by the difference between the probability density function (PDF) and the failure-conditional PDF. This derivation allows for TRS analysis to be performed with just one set of samples, where the computational complexity does not depend on the number of inputs. Then, the procedures for Monte Carlo simulation (MCS) are listed based on the innovative estimation of the sensitivity index. Three examples involving numerical and engineering problems are employed to validate the proposed strategy, with the direct MCS introduced for comparison. The results reveal that the proposed strategy provides satisfactory TRS analysis while significantly saving computational resources.

Effects of the Nonsteroidal MRA Finerenone With and Without Concomitant SGLT2 Inhibitor Use in Heart Failure.

Patients with heart failure (HF) with mildly reduced or preserved ejection fraction face heightened long-term risks of morbidity and mortality. Sodium-glucose cotransporter-2 inhibitors (SGLT2i) and the nonsteroidal mineralocorticoid receptor antagonist finerenone have both been shown to reduce the risk of cardiovascular events in this population, but the effects of their combined use are not known. FINEARTS-HF (Finerenone Trial to Investigate Efficacy and Safety Superior to Placebo in Patients With Heart Failure) was a randomized, double-blind, placebo-controlled trial of finerenone in patients with HF and left ventricular ejection fraction ≥40%. Baseline SGLT2i use was a prespecified subgroup. The primary outcome was a composite of total (first and recurrent) worsening HF events and cardiovascular death. We first assessed for evidence of treatment heterogeneity on the basis of baseline SGLT2i use. We further examined SGLT2i uptake during the trial and evaluated the treatment effects of finerenone accounting for baseline and during-trial use of SGLT2i in time-varying analyses. Among 6001 participants, 817 (13.6%) were treated with an SGLT2i at baseline. During 2.6 years median follow-up, treatment with finerenone similarly reduced the risk of the primary outcome in participants treated with an SGLT2i (rate ratio, 0.83 [95% CI, 0.60-1.16]) and without an SGLT2i at baseline (rate ratio, 0.85 [95% CI, 0.74-0.98]; Pinteraction=0.76). In follow-up, 980 participants initiated SGLT2i, which was less frequent in the finerenone arm compared with placebo (17.7% versus 20.1%; hazard ratio, 0.86 [95% CI, 0.76-0.97]). Time-updated analyses accounting for baseline and subsequent use of SGLT2i did not meaningfully alter the treatment effects of finerenone on the primary end point. The treatment benefits of the nonsteroidal mineralocorticoid receptor antagonist finerenone were observed irrespective of concomitant use of an SGLT2i. These data suggest that the combined use of SGLT2i and a nonsteroidal mineralocorticoid receptor antagonist may provide additive protection against cardiovascular events in patients with HF with mildly reduced or preserved ejection fraction. URL: https://www.clinicaltrials.gov; Unique identifier: NCT04435626.

Economic policy uncertainty and US sector REITs: what can we learn from spillovers?

PurposeThis study examines the impact of Economic Policy Uncertainty (EPU) on US Real Estate Investment Trust (REIT) sectors from 1994 to 2024, focusing on dynamic spillover effects across varying economic environments.Design/methodology/approachEmploying a time-varying parameter vector autoregression (TVP-VAR) model, the research analyzes sectoral interconnectedness and spillover dynamics, capturing the evolving relationships between REIT subsectors and EPU over time.FindingsThe analysis reveals that US REIT subsectors are highly interconnected, indicating substantial internal spillovers. Retail, regional malls and shopping centres are primary shock transmitters, while self-storage, manufactured homes and industrial REITs act as net receivers, demonstrating resilience. Over the study period, Economic Policy Uncertainty (EPU) generally functions as a net receiver of spillovers from REITs. However, pairwise time-varying analysis shows that EPU transmitted shocks during the economic uncertainties of the 1990s but became a net receiver during the 2008 financial crisis and the COVID-19 pandemic, suggesting that disruptions in REIT markets contributed to policy uncertainties during crises. Additionally, the sectors driving volatility shifted over time: residential and apartment REITs were predominant during the 2008 crisis, while disruptions in the office sector were significant during the pandemic.Practical implicationsPolicymakers ought to design targeted interventions to stabilize the sectors that are primary transmitters of shocks during economic downturns and monitor closely economic indicators and adopt policies to mitigate adverse spillover effects.Originality/valueThis study offers novel insights into the time-varying interconnections between REIT sectors and economic uncertainty, illustrating how these relationships evolve with economic conditions and enhancing understanding of REIT resilience under uncertainty.

Time-varying analyses of survival and outcomes in patients with HeartMate 3 left ventricular assist devices.

As patients experience longer survival on HeartMate 3 left ventricular assist devices, there is a need to characterize long-term risks of adverse outcomes more precisely. This study characterized temporal variations in risks of mortality and adverse outcomes in patients with a HeartMate 3. From October 2015 to January 2023, 431 HeartMate 3 devices were implanted at Cleveland Clinic. Survival was estimated to 5 years post-implant. Time-varying risks of death, neurological events, gastrointestinal bleeding, device-related infections, and other adverse events were characterized using multiphase hazard modelling. Survival on HeartMate 3 at 1 and 5 years was 88% and 58%, respectively. Risk of death peaked in the first postoperative month before declining rapidly to a constant, lower hazard. Cumulative number of neurological events/patient at 1 year and 5 years was 0.13 and 0.29, respectively; risk was highest within the first postoperative week, then rapidly declined by 1 month. Cumulative number of gastrointestinal bleeding events/patient at 1 year and 5 years was 0.32 and 0.78, respectively; risk was highest within 1 week postoperatively and gradually declined to a constant risk over the first year. Device-related infections developed in 136 patients. One- and 5-year freedom from device-related infection was 77% and 45%, respectively; risk was initially low before peaking at 6 months postoperatively and then gradually declining to a steady hazard. Long-term survival on HeartMate 3 support was favourable in a large single-centre cohort. Strategies to reduce early postoperative risk of neurological events and late risks of gastrointestinal bleeding, infections and other adverse events are needed.

Do Supply Chain Pressures Affect Consumer Prices in Major Economies? New Evidence from Time-Varying Causality Analysis

This study explores the dynamic causality between the consumer price index and supply chain pressure index in two large economies. Despite extensive research into the role of supply chains at the firm level, literature on their impact on time-varying inflation and macroeconomic stability is scarce. Using data from the United States and the European Union from January 2000 to December 2021, we employ novel time-varying causality techniques to examine the evolving relationships among inflation, supply chains, real gross domestic product, interest rates, and oil prices. Our findings show that supply chains have a significant dynamic relationship with consumer prices, particularly during economic crises like the 2008 global financial crisis and the COVID-19 pandemic. Robustness tests including impulse response functions and the autoregressive distributed lag model confirm this causality. These results are critical for policymakers, emphasizing the importance of supply chains in controlling inflation and achieving global economic resilience and stability.

Evaluating the Effectiveness of mRNA-1273.815 Against COVID-19 Hospitalization Among Adults Aged ≥ 18Years in the United States.

In September 2023 the Food and Drug Administration (FDA) approved an updated mRNA COVID-19 vaccine targeting the XBB.1.5 sublineage. This study evaluates the effectiveness of mRNA-1273.815, a 2023-2024 Omicron XBB.1.5-containing mRNA COVID-19 vaccine in preventing COVID-19-related hospitalizations and medically attended COVID-19 in US adults aged ≥ 18 years. This observational, matched cohort study used medical and pharmacy claims data from HealthVerity. Adults vaccinated with mRNA-1273.815 between September 12, 2023, and December 31, 2023, were followed through January 26, 2024. Vaccinated individuals were matched with individuals unvaccinated with any 2023-2024 COVID-19 vaccine on demographic and clinical characteristics. The primary and secondary outcomes were COVID-19 hospitalization and medically attended COVID-19, respectively. Inverse probability of treatment weighting and Cox proportional hazards regression were utilized to estimate vaccine effectiveness (VE). The study included 1,272,161 vaccinated individuals matched 1:1 with unvaccinated individuals, with a maximum follow-up of 128 (median 84)days. The VE against COVID-19 hospitalization was 51% (95% confidence interval [CI]: 48-54%). Subgroup analyses showed a VE of 56% (95% CI 51-61%) among adults ≥ 65 years and 46% (95% CI 39-52%) in immunocompromised adults. For medically attended COVID-19, the VE was 25% (95% CI 24-27%). Time-varying analyses showed that while VE declined over time, VE remained significant. During the 2023-2024 respiratory season, the mRNA-1273.815 vaccine significantly protected against COVID-19-related hospitalizations and medically attended COVID-19 across diverse adult populations and demonstrated durability of the effect. These results support the continued use of updated COVID-19 vaccines to mitigate severe outcomes and maintain public health safety.

Impact of Global Supply Chain Pressure on International Trade: Evidence from Turkey’s Container Traffic

I aimed to econometrically determine the reflection of pressure-increasing events in the global supply chain on the container traffic in Turkish ports, since any disruption or pressure can have negative consequences such as shortages and high prices for consumers, a decline in profitability for companies, reduced job opportunities for workers, a slowdown in economic growth for countries, and a slowdown in trade for the world. I used the Global Supply Chain Pressure Index (GSCPI) to model the impact of events occurring in the global supply chain, and the export and import container traffic at Turkish ports. Instead of examining the relationship between the variables over the whole sample, I used the time-varying causality analysis, which makes it possible to detect the relationship at different periods in time by analyzing it with the rolling window approach. The dataset includes 230 monthly observations and covers the period between January 2004 and February 2023. The pressure in the supply chain differs according to export and import container loads. The Russia–Ukraine war, the Suez Canal closure, economic sanctions between the U.S. and China, economic crisis, geopolitical conflicts, hurricanes, and port congestion in the U.S. all affected the traffic in Turkish ports. Since this research was conducted with a time-varying approach and the GSCPI variable successfully represented many global supply chain events, it was possible to examine which events affected international trade through a single variable. Thus, event-based assessments become possible instead of just saying that supply chain pressure affects international trade.

Differential long-term tamoxifen therapy benefit by menopausal status in breast cancer patients: secondary analysis of a controlled randomized clinical trial.

Estrogen receptor-positive breast cancer patients have a long-term risk of distant metastatic disease, and premenopausal patients have a higher risk. Randomized studies with long-term follow-up are essential to understand treatment benefit. We elucidated the long-term tamoxifen therapy benefit by menopausal status in the Stockholm tamoxifen trials with 20 years complete follow-up. Secondary analysis of 1242 estrogen receptor-positive and HER2-negative patients that were randomly assigned to 2-5 years of 40 mg adjuvant tamoxifen or no endocrine therapy. Distant recurrence-free interval in tamoxifen-treated vs endocrine untreated patients was assessed by Kaplan-Meier, Cox proportional hazards regression, and time-varying analyses. In premenopausal patients, a statistically significant tamoxifen benefit was observed for lymph node-negative (adjusted hazard ratio [HR] = 0.46, 95% confidence interval [CI] = 0.24 to 0.87), progesterone receptor-positive (adjusted HR = 0.61, 95% CI = 0.41 to 0.91), and genomic low-risk tumors (adjusted HR = 0.47, 95% CI = 0.26 to 0.85) but only lasted beyond 10 years for genomic low-risk tumors. Postmenopausal patients showed long-term benefit for all good-prognosis markers including low-grade (adjusted HR = 0.55, 95% CI = 0.41 to 0.73), lymph node-negative (adjusted HR = 0.44, 95% CI = 0.30 to 0.64), progesterone receptor-positive (adjusted HR = 0.60, 95% CI = 0.44 to 0.80), Ki-67 low (adjusted HR = 0.51, 95% CI = 0.38 to 0.68), and genomic low-risk tumors (adjusted HR = 0.53, 95% CI = 0.37 to 0.74), and regardless of tumor size (≤20 mm: adjusted HR = 0.55, 95% CI = 0.39 to 0.77; >20 mm: adjusted HR = 0.64, 95% CI = 0.44 to 0.94). Premenopausal patients with no poor-prognosis tumor characteristics (clinical marker score = 0) showed early benefit and postmenopausal long-term benefit. Our study suggests differential tamoxifen benefit by menopausal status. Improved long-term endocrine therapy prediction in premenopausal patients is needed and could involve molecular markers because standard tumor characteristics cannot predict benefit beyond 10 years.

Research on time-varying mesh stiffness analysis method of gears with local defective faults

Research on time-varying mesh stiffness analysis method of gears with local defective faults

Long-term benefit of SGLT2 inhibitors to prevent heart failure hospitalization in patients with diabetes, with potential time-varying benefit.

SGLT2 inhibitors show promise in reducing hospitalization for heart failure in diabetics, but their long-term effects and time-dependency remain unclear. We conducted a retrospective nested case-control study within a large type 2 diabetic cohort (n = 11,209) using electronic health records. Cases (heart failure hospitalization, n = 352) were matched to controls (n = 1372) based on age, sex, cohort entry date, and diabetes duration. Matched-set conditional logistic regression was used to estimate hazard ratios (HRs) for antidiabetic drug class and heart failure hospitalization risk. SGLT2 inhibitors were associated with a significant reduction in heart failure hospitalization risk (adjusted HR 0.56, 95% CI 0.38-0.82, p = 0.028). This protective effect appeared more pronounced with a longer duration of treatment, suggesting a potential cumulative benefit. Time-varying analysis within propensity score-matched cohorts revealed a progressive decrease in hospitalization risk with continued SGLT2 inhibitor use, indicating a strengthening effect over time (greedy nearest neighbor: HR 0.52, CI 0.31-0.87, p = 0.015; optimal matching: HR 0.54, CI 0.34-0.85, p = 0.008). While promising, further investigation with larger datasets is warranted to definitively confirm these findings.

Probabilistic analysis framework for the deterioration of marine tubular steel structures based on random field simulation

Corrosion reduces the effective cross-section, leading to the bearing capacity loss of marine tubular steel structures; the structures’ time-variant performance are of great concern in practices. The paper employs random field simulation to account for corrosion's spatial variability in evaluating the bearing capacity of the axially-loaded steel tubes, and proposes a time-variant reliability analysis framework for marine tubular steel structures, from the member-level to the structure-level. Results are compared with those neglecting the corrosion's spatial variability. The proposed method prevents a significant underestimation of the failure probability comparing to that neglecting spatial variability, and provides a tool for designers to predict the time-variant reliability levels for marine steel structures.

A Study on Nonlinearity in Mixers Using a Time-Varying Volterra-Based Distortion Contribution Analysis Tool

A Study on Nonlinearity in Mixers Using a Time-Varying Volterra-Based Distortion Contribution Analysis Tool

Gap filling between GRACE and GRACE-FO missions: assessment of interpolation techniques

We propose a benchmark for comparing gap-filling techniques used on global time-variable gravity field time-series. The Gravity Recovery and Climate Experiment (GRACE) and the GRACE Follow-On missions provide products to study the Earth’s time-variable gravity field. However, the presence of missing months in the measurements poses challenges for understanding specific Earth processes through the gravity field. We reproduce, adapt, and compare satellite-monitoring and interpolation techniques for filling these missing months in GRACE and GRACE Follow-On products on a global scale. Satellite-monitoring techniques utilize solutions from Swarm and satellite laser ranging, while interpolation techniques rely on GRACE and/or Swarm solutions. We assess a wide range of interpolation techniques, including least-squares fitting, principal component analysis, singular spectrum analysis, multichannel singular spectrum analysis, auto-regressive models, and the incorporation of prior data in these techniques. To inter-compare these techniques, we employ a remove-and-restore approach, removing existing GRACE products and predicting missing months using interpolation techniques. We provide detailed comparisons of the techniques and discuss their strengths and limitations. The auto-regressive interpolation technique delivers the best score according to our evaluation metric. The interpolation based on a least-squares fitting of constant, trend, annual, and semi-annual cycles offers a simple and effective prediction with a good score. Through this assessment, we establish a starting benchmark for gap-filling techniques in Earth’s time-variable gravity field analysis.

Information linkages across countries around net zero announcements

This study investigates the information linkages around net zero announcements across countries. Relying on rational expectation theory, this study employs the generalized method of moments (GMM) as well as the implied volatility approach to quantify volatility linkages between exchange-traded funds (ETFs) from nine countries and a global ETF (WLD). The GMM analysis reveals that volatility linkages among country ETFs and WLD range from 39.67 % to 71.43 %, while the implied volatility approach indicates that volatility linkages between markets range from 32.31 % to 65.36 %, indicating significant information spillover across countries. A time-varying dynamic analysis further shows that the US Government's net zero announcement increased volatility linkages across markets by 8.7 % to 58.05 %, signaling market approval of the US commitment to net zero targets. Multivariate analysis of the monthly correlation between country ETFs and WLD shows that the US plays a pivotal role. Although net zero announcements by the US, UK, and China individually impacted market correlations, the effect of China's announcement was insignificant when all announcements were considered in the model. Without US participation, efforts by other countries to achieve global net zero goals are unlikely to succeed.