en Public Administration & Health management and economics Public Administration & Health management and economics Original Research Original Research <p dir="ltr"><strong>Background: </strong>Based on the target income hypothesis, the economic behavior of physicians is mainly affected by their target income. This study aimed at designing an instrument to explain how general practitioners (GPs) set their desired income.<br> <strong>&nbsp;&nbsp; Methods:</strong> A self-administered questionnaire of affecting factors on GPs&#39; target income was extracted from literature reviews and a small qualitative study. Respondents were 666 GPs who completed the questionnaire (response rate= 52%) during 2 seasonal congresses of Iranian GPs. The principal component analysis (PCA) with varimax rotation was used to classify the variables and data reduction. Sample adequacy test, sphericity test, eigenvalues of components, and scree plot were evaluated for PCA. Cronbach&#39;s alpha was also checked to assess the internal consistency of the principal components.<br> <strong>&nbsp;&nbsp; Results:</strong> The results of the KMO measure of sampling adequacy (0.657) and Bartlett&rsquo;s test of sphericity (809.05, p<0.001) revealed that the collected data were suitable for PCA.<br> Based on the scree plot pattern and eigenvalues greater than 1, 6 components including perceived comparative income, importance of responsiveness to patients, perceived socioeconomic status, economic expectations, socioeconomic status of paternal family, and provision of luxury services were selected, which explained 65.19% of the total variance. Finally, only those with a Cronbach&#39;s alpha value higher than 0.6 were considered reliable (the first 4 components).&nbsp;<br> <strong>&nbsp;&nbsp; Conclusion:</strong> Based on the target income hypothesis, a physician&rsquo;s desired level of income affects their behavior. Our developed instrument and its mentioned components can be used in future studies related to GPs&#39; behavior, especially those studies related to the economic aspects of GPs&rsquo; behavior. It also helps formulate a better payment mechanism for primary care providers.&nbsp;<br> &nbsp;</p> General practitioner, Behavioral economics, Healthcare economics and organizations, Target income hypothesis, Principal component analysis 236 240 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-2680-1&slc_lang=en&sid=1 Mohsen Bayati bayatim66@gmail.com 200319475328460033920 200319475328460033920 No Department of Health Management and Economics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Arash Rashidian arash.rashidian@gmail.com 200319475328460033921 200319475328460033921 Yes Department of Health Management and Economics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Ali Akbari Sari akbarisari@tums.ac.ir 200319475328460033922 200319475328460033922 No Department of Health Management and Economics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Sara Emamgholipour s-emamgholipour@tums.ac.ir 200319475328460033923 200319475328460033923 No Department of Health Management and Economics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.