Replication data for: Statistical analysis of endorsement experiments: Measuring support for militant groups in Pakistan

Political scientists have long been interested in citizens' support level for socially sensitive actors such as ethnic minorities, militant groups, and authoritarian regimes. Attempts to use direct questioning in surveys, however, have largely yielded unreliable measures of these attitudes as they are contaminated by social desirability bias and high non-response rates. In this paper, we develop a statistical methodology to analyze endorsement experiments, which recently have been proposed as a possible solution to this measurement problem. The commonly used statistical methods are problematic because they cannot properly combine responses across multiple policy questions, the design feature of a typical endorsement experiment. We overcome this limitation by using item response theory to estimate support levels on the same scale as the ideal points of respondents. We also show how to extend our model to incorporate a hierarchical structure of data in order to recoup the loss of statistical eciency due to indirect questioning. We illustrate the proposed methodology by applying it to measure political support for Islamist milita nt groups in Pakistan. Simulation studies suggest that the proposed Bayesian model yields estimates with reasonable levels of bias and statistical power. Finally, we oer several practical suggestions for improving the design and analysis of endorsement experiments.政治学者长期以来一直关注公民对社会敏感行为体的支持程度，例如少数族裔、激进组织与威权政权。然而，在调查中采用直接提问的方式，往往只能得到这类态度的不可靠测量结果，因为这些测量会受到社会期许偏差（social desirability bias）与高无应答率（non-response rates）的干扰。本文中，我们开发了一套用于分析背书实验（endorsement experiments）的统计方法——这类实验近期被提出作为解决该测量难题的可行方案。当前常用的统计方法存在缺陷，因其无法恰当结合多个政策问题的应答数据，而这正是典型背书实验的核心设计特征。我们通过采用项目反应理论（item response theory），在与受访者理想点相一致的量表上估算支持水平，以此克服这一局限。我们还展示了如何将所提模型扩展以纳入数据的层级结构，从而弥补间接提问所带来的统计效率损失。我们通过将该方法应用于巴基斯坦境内伊斯兰激进武装组织的政治支持度测量，演示了所提方法的具体使用。仿真研究表明，所提出的贝叶斯模型（Bayesian model）所得到的估计值，其偏倚水平与统计功效均处于合理区间。最后，我们为优化背书实验的设计与分析提供了若干实操建议。