scholarly journals Synthetic Controls with Staggered Adoption

2021 ◽  
Author(s):  
Eli Ben-Michael ◽  
Avi Feller ◽  
Jesse Rothstein
Keyword(s):  
Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1305
Author(s):  
Feliu Serra-Burriel ◽  
Pedro Delicado ◽  
Fernando M. Cucchietti

In recent years, wildfires have caused havoc across the world, which are especially aggravated in certain regions due to climate change. Remote sensing has become a powerful tool for monitoring fires, as well as for measuring their effects on vegetation over the following years. We aim to explain the dynamics of wildfires’ effects on a vegetation index (previously estimated by causal inference through synthetic controls) from pre-wildfire available information (mainly proceeding from satellites). For this purpose, we use regression models from Functional Data Analysis, where wildfire effects are considered functional responses, depending on elapsed time after each wildfire, while pre-wildfire information acts as scalar covariates. Our main findings show that vegetation recovery after wildfires is a slow process, affected by many pre-wildfire conditions, among which the richness and diversity of vegetation is one of the best predictors for the recovery.


2021 ◽  
Vol 111 ◽  
pp. 514-519
Author(s):  
Caroline Fohlin ◽  
Zhikun Lu

Using a new dataset of all NYC trust company stocks, we study the impact of the Panic of 1907 and the ensuing cash infusion by JP Morgan and the Treasury. Using synthetic controls, we find that three “troubled” trusts performed far worse than the other trusts, whose valuations rebounded within a year. Moreover, trust companies connected to “money trust” banks maintained higher valuation than independents and rebounded much faster. The desire to prevent panic from spreading from infected trusts to financial institutions in his purview could explain Morgan's rapid intervention to stem the contagion.


Author(s):  
Glenn J. Lematta ◽  
Craig J. Johnson ◽  
Erin K. Chiou ◽  
Nancy J. Cooke

Project overview As a team explores interactions, they may find opportunities to expand and refine teamwork over time. This can have consequences for team effectiveness in normal and unexpected situations (Woods, 2018). Understanding the role of exploratory team interactions may be relevant for human-autonomy team (HAT) resilience in the face of synthetic agent rigidity and lack of anticipation (Demir et al, 2019). Team interaction exploration was defined as team interactions with qualities (e.g. content, communication medium) unique to a team’s interaction history (Cooke et al., 2013; Hills et al., 2015). This study examines the relationship between team interaction exploration and HAT performance in multiple remotely-piloted aerial system (RPAS) reconnaissance missions with degraded conditions. The goal of the task was to take good photos of target waypoints. In this task, three teammates are assigned to specific roles: the navigator plans the route using a digital map, the pilot (synthetic) controls the RPAS and selects target waypoints, and the photographer calibrates camera settings to take a good photo of a target waypoint. The synthetic agent was capable of routine team coordination without explicit team player qualities. Teams communicated via a text-chat interface. Seven unique degraded conditions were injected throughout ten missions. Three automation failures disrupted RPAS status information on the photographer’s or pilot’s display, and three autonomy failures disrupted the synthetic agent’s comprehension of waypoint information or caused the agent to move on to the next target before a photo was taken. Finally, a malicious cyber-attack caused the synthetic agent to fly the RPAS to an enemy occupied waypoint. Method Forty-four participants were recruited from a large southwestern university in pairs and formed teams (22 teams) to participate in this study. These participants were either undergraduate or graduate students. This experiment consisted of ten 40-minute missions in total that were carried out over two sessions separated by one-to two-week intervals. After a baseline mission, an automation and autonomy failure was injected into each mission while the team processed target waypoints. The malicious cyber-attack occurred during the final 20-minutes of the tenth mission. This study collected a several measures including measures of team process, physiological measures, and surveys of teamwork knowledge, trust, workload, and anthropomorphism which are not considered in this study. Exploratory team interaction was operationalized as any text-message unique in content, sender, or recipient that was unrelated to routine coordination of target waypoints. Teams were grouped using k-means clustering by their target processing efficiency, number of overcome roadblocks, and mission performance. The three clusters ( K = 3) were comparatively described as low- ( N = 7), middle- ( N = 7), and high-performing ( N = 5) teams. A mixed-factor ANOVA compared the frequency of each team’s exploratory interactions by mission and cluster. Results and discussion High-performing teams were distinguished from middle-and low-performing teams in their ability to maintain high levels of overall performance while efficiently processing targets and overcoming many roadblocks. Middle-performing teams were efficient in overcoming roadblocks but had worse mission performance. The findings indicate that 1) high-performing teams explored team interactions more than middle-performing teams, 2) there was no significant difference in exploration frequency between high-and low-performing teams, and 3) teams explored more in the first session than the second session, with the exception of the final mission. Overall, exploratory team interaction differentiated HAT performance in normal and degraded conditions and should be further examined at other levels of interaction, such as content meaning and interaction patterns.


2015 ◽  
Vol 47 (4) ◽  
pp. 749-782
Author(s):  
Paul Zachary ◽  
Kathleen Deloughery ◽  
Alexander B. Downes

Scholars argue that states undertake foreign military interventions for economic reasons, yet few have investigated whether intervention produces economic benefits. This article answers this question in the context of US foreign-imposed regime changes (FIRCs) in Latin America. Because FIRCs install leaders who are sympathetic to the intervener’s interests, economic arguments maintain that these interventions should increase bilateral trade between the targets and imposing countries. Yet security-based arguments assert that FIRCs should have little economic effect, as regime changes target threats rather than generate economic benefits. A third perspective argues that FIRCs reduce trade by generating political instability, which causes foreign firms to cut back on their involvement and domestic firms to experience difficulty getting goods to market. To test these competing arguments, this study employs a novel dataset on bilateral trade (1873–2007) compiled through archival research in Washington, DC. Using a gravity model and synthetic controls, it finds that FIRC produces an average decrease of 45 per cent in the dollar value of bilateral trade. Further analysis of archival sector-level data and case studies cast doubt on alternate explanations.


Author(s):  
Michael Peake ◽  
Beryl Mazzachi ◽  
Andrew Fudge ◽  
Renze Bais

The reliability of a recently released total bilirubin assay for a blood gas analyser was assessed in two Australian hospital laboratories. The instrument computes total bilirubin concentration from multi-wavelength absorbance measurements of undiluted whole blood or plasma. Performance of the Radiometer ABL 735 blood gas analyser bilirubin method (software version 3.6) was compared with a proven Roche diazo method for Hitachi analysers, calibrated using primary standards prepared from NIST SRM 916a bilirubin. Acceptable bilirubin results were found over a wide concentration range for most neonatal samples of whole blood or plasma. For adult specimens, bilirubin results were approximately 10% lower on the blood gas analyser. Within-run imprecision (whole blood) was <2·5%, between-day imprecision (synthetic controls) <1·0%, and the bilirubin assay for both whole blood and plasma was linear to 1000μmol/L. Using sampling options from 35 μL to 195μL, bilirubin results differed by less than 3%, with a 95 μL syringe option producing the highest results. We conclude that the Radiometer ABL 735 bilirubin assay is suitable for near-patient assessment of neonatal jaundice using whole blood, thus eliminating the need for sample centrifugation. Verification using laboratory methods can be used when required. A positive correction of approximately 10% is required for adult specimens to conform with Hitachi results (SRM 916a calibration), possibly due to the optical characteristics of the higher proportion of conjugated bilirubin and other substances present in most adult samples.


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