*3.1. Case Background*

At the beginning of 2020, the outbreak of COVID-19 brought grea<sup>t</sup> impact on people's life and work. In order to contain the spread of novel coronavirus and speed up the normalization of production and life, on 7 February 2020, Yuhang first launched the Yuhang Health Code. And on 11 February 2020, Hangzhou launched the Hangzhou Health Code to implement "green code, red code, yellow code" three-color code dynamic managemen<sup>t</sup> [18]. The implementation of this policy has aroused widespread concern of the people all over the country, and local governments have followed up and implemented a local version of code in few weeks [18]. The implementation of Health Code policy is

assisted by the QR rating health code system developed by Alibaba, Tencent, or other firms. When registering, individuals should provide their names, ID numbers, phone numbers, and answer a series questions about physical health conditions and travel trajectory to ge<sup>t</sup> the initial rating [54]. In addition, the rating changes according to individual real-time data, which consists of individuals' travel history, directly related health information, overall medical test results, and overall risk assessment from individuals' reports, information from GPS (Global Positioning System), telecommunications supplier, consumption record, QR code usage record, etc. The system assesses individual's infection risk and generates green, yellow, or red codes according to individual's data [55]. People with green codes have a very low probability to be infected and can move around freely, while people with yellow codes have a risk to be infected to some extent and should be quarantined for a week. People with red codes are at grea<sup>t</sup> risk of infection and need to be quarantined for 2 weeks. During the quarantine, if people with yellow or red codes check in on the app every day, the codes will turn green at the end of quarantine periods. And if the real-time information shows that people with green codes have gone to a high-risk area or been in contact with an infected person, the code will turn yellow or red as well [10]. Up to August 2020, the Tencent Health Code covers a population of 9 hundred million people, more than 400 cities and counties, and more than 5100 villages in China, with a cumulative total of 42 billion visits [56]. With the evolution of the Health Code policy, the e ffective circulation of personnel from all over the country has met the needs of residents' normal life and enterprises' resumption of work and production. At present, residents only need to provide a real-time QR code generated in a mini-app embedded in Alipay (Alibaba, Hangzhou, China) or WeChat (Tencent, Shenzhen, China) to the guard, they can move around [54]. In the Health Code policy implementation process, the high-tech enterprises not only provide technical support to develop the health code system, but also participate in the formulation of policy standards and establishment of policy platforms. For example, Alibaba and Tencent have been fully involved in the formulation of national standards for the personal Health Information Code series [57,58]. Besides, during this process, the public is actively voicing on the implementation and evolution of the Health Code policy as well as improvements of health code application on social media. In the o fficial Weibo of People's Daily, tweets about the Health Code policy ge<sup>t</sup> plenty of comments and followers, most of which are advice for policy implementation and system improvement. For example, the tweet about the Hangzhou Health Code has 7227 comments and 79,547 followers. The governmen<sup>t</sup> press conference and reports about enterprises confirm the public voice does play an important role in the evolution and promotion of Health Code policy and the voice is fully considered and adopted by governmen<sup>t</sup> and enterprises when making decisions. On the joint prevention and control conferences of COVID-19, the governmen<sup>t</sup> spokespersons provided response to public concern and the governments also instructed local governmen<sup>t</sup> and related enterprises to take measures to meet public voice. In addition, the enterprises responded to public voice as well. In the Government A ffairs Strategy Conference, Yuepeng Qiu, vice President of Tencent, said that they had updated the system more than 50 times.

#### *3.2. Data Collection and Analysis*

This study adopts a dynamic research perspective, and takes the dynamic evolution of health codes policy as an example, focusing on exploring how public voice promoted the improvement of products by enterprises and the implementation of policies by the governmen<sup>t</sup> under a public health emergency. The core of grounded theory emphasizes the process of collecting and analyzing original data. In the data collection stage, the researcher takes the evolution process of the Health Code policy as the time axis, and collects public comments under the o fficial microblog of the People's Daily as the research object. Data analysis included the following stages: Firstly, open coding is used to identify phenomena, define concepts, and discover categories from the original data. Secondly, axial coding is carried out to further analyze to ge<sup>t</sup> the main category. Thirdly, selective coding is used to find the core category, and systematically connect it with other categories to construct a logical relationship. In the whole coding process, researchers keep supplementing the material. Finally, the selective coding is

analyzed and theoretical construction is carried out, and the density, variation, and high integration of theoretical concepts are adjusted to form a theoretical framework. The qualitative analysis software Nvivo 11.0 (QSR International, Melbourne, Australia) was used for the analysis of this study.
