Placebo analysis for causal inference in tourism
本文为旅游研究中的安慰剂检验提供了一个结构化框架，包括分类清单和操作步骤，并通过蓝旗生态标签与意大利沿海省份国际旅游流关系的重分析加以说明，旨在帮助研究者评估因果估计的可信度。
This paper proposes a structured framework for implementing placebo tests as diagnostic tools to assess the robustness of empirical analyses in tourism research. Building on the taxonomy of Eggers et al. (2024), we distinguish between treatment, outcome, and population placebos and translate these categories into a practical checklist that guides researchers from clarifying assumptions to designing suitable placebo scenarios. To illustrate the approach, we reconstruct and reanalyze the relationship between Blue Flag eco-labels and international tourism flows to Italian coastal provinces. The example does not aim to generate new substantive insights on eco-labels; rather, it demonstrates how placebo tests can be embedded within a transparent and systematic procedure to evaluate the credibility of estimated effects. By offering a step-by-step guide and an applied illustration, the paper encourages a more disciplined, transparent, and methodologically informed use of placebo tests in observational tourism research.