Browsing by Author "Liu, Z"
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Item Open Access A stochastic version of Stein Variational Gradient Descent for efficient samplingLi, L; Li, Y; Liu, JG; Liu, Z; Lu, JWe propose in this work RBM-SVGD, a stochastic version of Stein Variational Gradient Descent (SVGD) method for efficiently sampling from a given probability measure and thus useful for Bayesian inference. The method is to apply the Random Batch Method (RBM) for interacting particle systems proposed by Jin et al to the interacting particle systems in SVGD. While keeping the behaviors of SVGD, it reduces the computational cost, especially when the interacting kernel has long range. Numerical examples verify the efficiency of this new version of SVGD.Item Open Access Beyond technological relatedness: An evolutionary pro-growth coalition and industrial transformation in Kunshan, China(Growth and Change, 2021-12-01) Wang, CC; Gereffi, G; Liu, ZThe article develops an analytical framework for an adaptable and evolutionary pro-growth coalition led by local government to understand regional industrial transformation in developing China. Taking Kunshan as an example, we argue that evolutionary and adaptable coalitions were key to Kunshan's successful transformation from an agriculture county to an export-oriented industrial center, and to a more diversified city. The coalition of the local state with land-holding farmers, domestic and international firms, and the central government during the 1980s-1990s laid a foundation for industrial transformation; the strong coalition of local state and Taiwanese investors in the 1990s-2000s shaped its new industry of IT manufacturing; and the coalition of local state with multiple actors at various geographical scales contributed a more diversified and innovative industrial structure of Kunshan. This study highlights that industrial evolution is not only driven by technological relatedness but also by the evolutionary state-led coalition of multiple actors from different levels and at different stages, and appeals for a political economy perspective to understand industrial transformation of resource- scarce regions.Item Open Access Notching R&D Investment with Corporate Income Tax Cuts in China(American Economic Review, 2021-07-01) Suarez Serrato, JC; Chen, Z; Liu, Z; Xu, DYWe analyze the effects of a large fiscal incentive for R&D investment in China that awards a lower average corporate income tax rate to qualifying firms. The sharp incentives of the program generate notches, or jumps, in firm values, and vary over time and across firm characteristics. We exploit a novel link between survey and administrative tax data of Chinese firms to estimate investment responses, the potential for evasion, as well as effects on productivity and tax payments. We find large responses of reported R&D using a cross-sectional “bunching” estimators that is new in the R&D literature. We also find evidence that firms relabel administrative expenses as R&D to qualify for the program. We estimate an intent-to-treat effect of the policy on R&D investment of 18.8%, and find that 45% of this response is due to evasion. These effects imply user-cost-elasticities of 2 for the reported response, and 1.14 for the real response. We utilize the panel structure of the data to estimate the effect of the program on firm productivity, and find an increase of 1.6% for targeted firms. These estimates are crucial ingredients for designing policies that trade-off corporate tax revenue with future productivity growth.Item Open Access Viewing the Role of Alternate Care Service Pathways in the Emergency Care System through a Causal Loop Diagram Lens(Systems) Kumar, A; Liu, Z; Ansah, JP; Ng, YY; Leong, BSH; Matchar, DB; Ong, MEH; Siddiqui, FJGlobally, Emergency Care Systems (ECS) are a critical resource that needs to be used judiciously as demand can easily exceed supply capacity. Sub-optimal ECS use contributes to Emergency Department (ED) crowding; this adversely affects ECS as well as system-wide service performance. Alternate Care Service Pathways (ACSPs) are innovations intended to mitigate ED crowding by re-routing less-urgent cases to sites of care other than the ED. As in other countries, policymakers in Singapore need to respond to increasing ED utilization and are evaluating the introduction of ACSPs. However, developing ACSPs is costly, entails tinkering with established critical services, and runs the risk of unintended adverse consequences. Through a Causal Loop Diagram (CLD) developed in four stages, we present a view of the current Singapore ECS and the intended role of ACSPs in relieving its stress. This exercise suggests that to be successful ACSPs must change the prevailing mental model of the ED as a “one-stop shop” but should focus on integrating with primary care. The discussions stimulated by the development, critiquing, and revision of the CLD highlighted the importance of accounting for the reservations of stakeholders for changes. The CLD has enhanced shared understanding and will be used to guide quantitative simulation modeling to promote informed policy.