scholarly journals Does city lockdown prevent the spread of COVID-19? New evidence from the synthetic control method

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Xiaoxuan Yang
Keyword(s):  
Control Method ◽  
Human Mobility ◽  
Initial Period ◽  
Sample Selection ◽  
Weighted Average ◽  
Synthetic Control ◽  
Population Mobility ◽  
Effective Response ◽  
Control Approach ◽  
Suppression Effect

Abstract Background At 10 a.m. on January 23, 2020 Wuhan, China imposed a 76-day travel lockdown on its 11 million residents in order to stop the spread of COVID-19. This lockdown represented the largest quarantine in the history of public health and provides us with an opportunity to critically examine the relationship between a city lockdown on human mobility and controlling the spread of a viral epidemic, in this case COVID-19. This study aims to assess the causal impact of the Wuhan lockdown on population movement and the increase of newly confirmed COVID-19 cases. Methods Based on the daily panel data from 279 Chinese cities, our research is the first to apply the synthetic control approach to empirically analyze the causal relationship between the Wuhan lockdown of its population mobility and the progression of newly confirmed COVID-19 cases. By using a weighted average of available control cities to reproduce the counterfactual outcome trajectory that the treated city would have experienced in the absence of the lockdown, the synthetic control approach overcomes the sample selection bias and policy endogeneity problems that can arise from previous empirical methods in selecting control units. Results In our example, the lockdown of Wuhan reduced mobility inflow by approximately 60 % and outflow by about 50 %. A significant reduction of new cases was observed within four days of the lockdown. The increase in new cases declined by around 50% during this period. However, the suppression effect became less discernible after this initial period of time. A 2.25-fold surge was found for the increase in new cases on the fifth day following the lockdown, after which it died down rapidly. Conclusions Our study provided urgently needed and reliable causal evidence that city lockdown can be an effective short-term tool in containing and delaying the spread of a viral epidemic. Further, the city lockdown strategy can buy time during which countries can mobilize an effective response in order to better prepare. Therefore, in spite of initial widespread skepticism, lockdowns are likely to be added to the response toolkit used for any future pandemic outbreak.

scholarly journals The effect of reduced unemployment duration on the unemployment rate: a Synthetic Control Approach

2020 ◽  
Vol 9 (1) ◽  
pp. 46-73
Author(s):  
Luzius Stricker ◽  
Moreno Baruffini
Keyword(s):  
Unemployment Rate ◽  
Control Method ◽  
Weighted Average ◽  
Control Unit ◽  
Unemployment Duration ◽  
Control Group ◽  
Synthetic Control ◽  
Donor Pool ◽  
Control Approach ◽  
The Impact

This paper examines the impact of the fourth partial revision of the law of unemployment insurance (AVIG) on unemployment dynamics in Switzerland at a cantonal level. The authors apply the Synthetic Control Method (SCM), a matching method for comparative case studies. A counterfactual analysis of the cases studied is performed by combining a control group of several untreated units, which provides a better comparison to the treatment group than a single unit. The control unit is designed as a weighted average of the available cantons in the donor pool, taking into account the similarities between the chosen controls and the treated unit. Once policy changes are controlled, the results suggest a significant effect on the unemployment rate at a cantonal level: the reform had a discernible impact on lowering the unemployment rate in the Italian- and French-speaking cantons in Switzerland.

scholarly journals The effect of an electricity tax on aggregate electricity consumption: evidence from Basel

2020 ◽  
Vol 156 (1) ◽  
Author(s):  
Benjamin Krebs ◽  
Simon Luechinger
Keyword(s):  
Price Elasticity ◽  
Control Method ◽  
Electricity Consumption ◽  
Weighted Average ◽  
Synthetic Control ◽  
Hypothetical Situation ◽  
Electricity Prices ◽  
Synthetic Control Method ◽  
Insignificant Effect

AbstractWe estimate the effect of an electricity tax on aggregate electricity consumption with the synthetic control method. The tax was introduced in the Swiss city of Basel in 1999 and, together with other tariff changes, increased marginal electricity prices by 5.4–8.0%. We compare the actual and a hypothetical electricity consumption in the years 1999–2006. The latter is a weighted average of electricity consumption in other Swiss cities and captures the hypothetical situation without the tax. We find a statistically insignificant effect of the tax increase of − 2.7 to − 1.9%, which implies a rather small, but not unreasonable, price elasticity of between − 0.5 and − 0.2. Ambiguous effects on average prices and an unfortunate communication by officials may explain why the innovative reform failed to induce a stronger response.

BACKSTEPPING CONTROLLER WITH PSO FOR AN UNDERACTUATED X4-AUV

2016 ◽  
Vol 78 (6-13) ◽  
Author(s):  
Nur Fadzillah Harun ◽  
Zainah Md. Zain
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Control Method ◽  
Fitness Function ◽  
Control Technique ◽  
Underactuated System ◽  
Effective Response ◽  
Control Approach ◽  
Comparison Results ◽  
Highly Nonlinear ◽  
Backstepping Controller

X4-AUV is a type of an autonomous underwater vehicle (AUV) which has 4 inputs with six degrees of freedoms (6-DOFs) in motion and is classified under an underactuated system. Controlling an underactuated AUV is difficult tasks because of the highly nonlinear dynamic, uncertainties in hydrodynamics behaviour and mostly those systems fails to satisfy Brockett’s Theorem. It usually required a nonlinear control approach and this paper proposed a backstepping control method with Particle Swarm Optimization (PSO) to stabilize an underactuated X4-AUV system. In backstepping controller design, accurate parameters are important in order to obtain the maximal and effective response. Hence, PSO is implemented to obtain optimal parameters for backstepping controller and its carry out by minimizing the fitness function. Comparison results illustrated the controller with PSO has a smooth and fast transient response into the desired point compared than manually tune controller parameters and also improve the system performances. The validity of the proposed control technique for an underactuated X4-AUV demonstrates through simulation.

Government-Created Nonprofit Organizations and Public Service Turnaround: Evidence from a Synthetic Control Approach

2020 ◽  
Author(s):  
José M Alonso ◽  
Rhys Andrews
Keyword(s):  
Nonprofit Organizations ◽  
Public Services ◽  
Local Community ◽  
Control Method ◽  
Synthetic Control ◽  
Control Approach ◽  
For Profit ◽  
Performance Effects ◽  
Education Authority ◽  
Collaborative Capabilities

Abstract Theories of sectoral advantage and failure suggest that collaborations between public and nonprofit organizations can create new collaborative capabilities that compensate for sector-specific weaknesses. Drawing on these perspectives, we investigate whether government-created nonprofit organizations (GCNPOs) can turn around public services regarded as “failing” by government agencies. In doing so, we analyze the transfer of all of the functions of a “failing” inner London local education authority (Hackney) to a specially created not-for-profit organization (the Learning Trust) responsible for all the primary and high schools within its jurisdiction (circa 60 schools, with about 25,000 pupils). Using a synthetic control method approach to investigate the performance effects of this intervention, we find that educational outcomes improved in Hackney during the years following the creation of the Learning Trust. Documentary evidence suggests that the nonprofit form of the Learning Trust may have enabled it to develop better relations with the local community and access new revenue streams, which helped to improve outcomes. Our findings highlight the breadth and depth of the contribution that GCNPOs can make to the delivery of public services and to their potential effectiveness in helping to turnaround those that are failing.

scholarly journals Evaluating the Effect of Homicide Prevention Strategies in São Paulo, Brazil: A Synthetic Control Approach

2016 ◽  
Author(s):  
Danilo Freire
Keyword(s):  
State Government ◽  
Control Method ◽  
Sao Paulo ◽  
The State ◽  
Synthetic Control ◽  
São Paulo ◽  
Prevention Strategies ◽  
Homicide Rates ◽  
Synthetic Control Method ◽  
Control Approach

Although Brazil remains severely affected by civil violence, the state of São Paulo has made significant inroads into fighting criminality. In the last decade, São Paulo has witnessed a 70% decline in homicide rates, a result that policy-makers attribute to a series of crime-reducing measures implemented by the state government. While recent academic studies seem to confirm this downward trend, no estimation of the total impact of state policies on homicide rates currently exists. The present article fills this gap by employing the Synthetic Control Method to compare these measures against an artificial São Paulo. The results indicate a large drop in homicide rates in actual São Paulo when contrasted with the synthetic counterfactual, with about 20,000 lives saved during the period. The theoretical usefulness of the Synthetic Control Method for public policy analysis, the role of the Primeiro Comando da Capital as a causal mediator, and the practical implications of the security measures taken by the São Paulo state government are also discussed.Keywords: Brazil, homicides, PCC, synthetic control, urban violenceReplication files: https://github.com/danilofreire/homicides-sp-synthCitation: Freire, Danilo. 2016. “Evaluating the Effect of Homicide Prevention Strategies in São Paulo, Brazil: A Synthetic Control Approach.” http://osf.io/8tmhe/@misc{freire2016evaluating, title={{Evaluating the Effect of Homicide Prevention Strategies in São Paulo, Brazil: A Synthetic Control Approach}}, howpublished = {\url{https://osf.io/vxe56}}, publisher={Open Science Framework}, author={Freire, Danilo}, year={2016}, month={Dec}}

scholarly journals Risk mapping for COVID-19 outbreaks in Australia using mobility data

2021 ◽  
Vol 18 (174) ◽  
pp. 20200657
Author(s):  
Cameron Zachreson ◽  
Lewis Mitchell ◽  
Michael J. Lydeamore ◽  
Nicolas Rebuli ◽  
Martin Tomko ◽  
...  
Keyword(s):  
Simple Procedure ◽  
Human Mobility ◽  
Transmission Risk ◽  
Population Mobility ◽  
Effective Response ◽  
Geographical Patterns ◽  
Mobility Data ◽  
Community Transmission ◽  
Geographically Targeted ◽  
Spatial Transmission

COVID-19 is highly transmissible and containing outbreaks requires a rapid and effective response. Because infection may be spread by people who are pre-symptomatic or asymptomatic, substantial undetected transmission is likely to occur before clinical cases are diagnosed. Thus, when outbreaks occur there is a need to anticipate which populations and locations are at heightened risk of exposure. In this work, we evaluate the utility of aggregate human mobility data for estimating the geographical distribution of transmission risk. We present a simple procedure for producing spatial transmission risk assessments from near-real-time population mobility data. We validate our estimates against three well-documented COVID-19 outbreaks in Australia. Two of these were well-defined transmission clusters and one was a community transmission scenario. Our results indicate that mobility data can be a good predictor of geographical patterns of exposure risk from transmission centres, particularly in outbreaks involving workplaces or other environments associated with habitual travel patterns. For community transmission scenarios, our results demonstrate that mobility data add the most value to risk predictions when case counts are low and spatially clustered. Our method could assist health systems in the allocation of testing resources, and potentially guide the implementation of geographically targeted restrictions on movement and social interaction.

Brazil, BITs and FDI: A Synthetic Control Approach

2019 ◽  
Vol 20 (1) ◽  
pp. 68-97
Author(s):  
Paulo Cavallo
Keyword(s):  
Foreign Direct Investment ◽  
Comparative Analysis ◽  
Direct Investment ◽  
Control Method ◽  
Synthetic Control ◽  
Synthetic Control Method ◽  
Foreign Investors ◽  
Fdi Inflows ◽  
Control Approach ◽  
Peculiar Case

Abstract The explosion in bilateral investment treaties (BITs) signed between countries in the 1990s and the concurrent surge in foreign direct investment (FDI) flows draw substantial attention in the literature. This article tackles the controversial relationship between BITs and FDI inflows using an innovative technique: the synthetic control method. Brazil is a peculiar case because it is one of the few cases where FDI inflows had a significant surge even in the complete absence of BITs. Did foreign investors really not need BITs in order to invest in Brazil? I find evidence that, although Brazil received substantial amounts of FDI even in the absence of BITs, had they enacted any BIT, the inflow in the period would have been greater. The method builds a synthetic Brazil from a pool of other countries providing this way a better comparative analysis. The findings are robust to both in-space and in-time placebo experiments.

Effect of Shanxi pilot emission trading scheme on industrial soot and dust emissions: A synthetic control method

2019 ◽  
Vol 31 (3) ◽  
pp. 461-478
Author(s):  
Xiao Cheng ◽  
Yanping Pu ◽  
Ran Gu
Keyword(s):  
Control Method ◽  
Emission Trading ◽  
Shanxi Province ◽  
Emission Trading Scheme ◽  
Synthetic Control ◽  
Synthetic Control Method ◽  
Dust Emissions ◽  
Control Approach ◽  
Pilot Work ◽  
Trading Scheme

To launch the nationwide emission trading scheme, some provinces in China were approved to design their pilot work for emission trading scheme according to local circumstances. Shanxi Province is the only pilot area with provincial trading market for industrial soot and dust emissions. This paper investigates the effect of Shanxi Pilot emission trading scheme on industrial soot and dust emissions by using the synthetic control method. The idea behind the synthetic control approach is to construct a combination of comparison cities to approximate the emission paths that the cities in Shanxi would have experienced in the absence of the pilot emission trading scheme. We demonstrate that, following Shanxi Pilot emission trading scheme, industrial soot and dust emissions fell markedly in Taiyuan, Datong, and Linfen relative to the synthetic counterparts. The finding that emission trading scheme can help achieve emission reduction targets is shown to be robust to the reduction in the number of control units, placebo tests, and difference-in-differences estimation.

Finally, Nebraska: A Synthetic Control Analysis of Legislative Structure

2019 ◽  
Vol 20 (1) ◽  
pp. 3-22
Author(s):  
William B. Hankins
Keyword(s):  
Control Method ◽  
Weighted Average ◽  
Sharp Decrease ◽  
Effect Estimate ◽  
Control Analysis ◽  
Synthetic Control ◽  
Per Capita ◽  
The Difference ◽  
Legislative Structure ◽  
The Impact

I estimate the impact of Nebraska’s 1937 switch from a bicameral to a unicameral legislature on state-level government expenditures. Using the synthetic control method I create a counterfactual Nebraska from a weighted average of other potential control states and compare spending in this “synthetic Nebraska” to spending in the real Nebraska. Relative to the synthetic control, Nebraska experiences a sharp decrease in expenditures per capita immediately following the switch to a unicameral legislature; however, the difference appears to diminish over time. Placebo tests show that if the change in Nebraska’s legislative structure were randomly assigned among the sample of states, and legislative structure had no real impact on spending, the likelihood of obtaining a treatment-effect estimate as large as Nebraska’s would be 0.0213. While the initial drop in expenditures per capita lends support to the theory that bicameralism, by requiring more veto players, is associated with higher levels of government spending, the fact that the difference between Nebraska and synthetic Nebraska diminishes suggests that legislators are able to circumvent this constraint.

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