[A]ccountability, democratic governance, efficient, and transparent legal structures and therefore trust within the society.
That is from the new paper: "Tax Morale and Compliance: Review of Evidence and Case Studies for Europe" by Benno Torgler.
The paper concludes:
A failure of a country‘s legal system undermines tax morale and tax compliance . . . Social norms or social capital are key factors in understanding the motivation for compliance in transition countries and other regions . . .
The tax morale index is based on the following:
From the The World Values Survey
―Please tell me for each of the following statements whether you think it can always be justified, never be justified, or something in between: ... Cheating on tax if you have the chance‖. The question leads to a ten scale index of tax morale with the two extreme points ―never justified‖ and ―always justified.
―On a scale of 1 to 10, where 1 means not at all justifiable and 10 means totally justifiable, how justifiable do you believe it is to: Manage to avoid paying all his tax‖.
International Social Survey Programme (ISSP)
―Do you feel it is wrong or not wrong if a taxpayer does not report all of his or her income in order to pay less income taxes? (1= not wrong, 2= a bit wrong, 3= wrong, 4=seriously wrong).