Replication Data for: The Differential Impact of the Hong Kong National Security Law on Political Sensitivity Bias in Local Opinion Polls

Political sensitivity bias is defined as the difference between observed poll results and genuine public opinion due to perceived state pressure on respondents. This bias misguides political scientists and politicians, leading to inaccurate assessments of political climates. Hong Kong, having experienced a rapid reduction in freedom of speech, provides a unique case for studying political sensitivity bias. This paper provides alternative evidence of such bias in Hong Kong by investigating the differential impact of the Hong Kong National Security Law, enacted in June 2020, on local opinion polls. This study uses open public poll data from the Hong Kong Public Opinion Research Institute (HKPORI) and the synthetic difference-in-differences (SDID) estimation to quantitatively assess the heterogeneous impact. Results indicate a significant positive differential treatment effect on the rejection of Taiwan and Tibet independence in polls, implying that the Hong Kong National Security Law has contributed to the increased political sensitivity bias in these polls, thereby proving the existence of such bias.