"Intrinsic Motivations of Public Sector Employees: Evidence for Germany " by Robert Dur and Robin Zoutenbierz (December 6, 2012: http://www.roa.unimaas.nl/seminars/pdf2013/Robert%20Dur.pdf)
Abstract: "We examine differences in altruism and laziness between public sector employees and private sector employees. Our theoretical model predicts that the likelihood of public sector employment increases with a worker's altruism, and increases or decreases with a worker's laziness depending on his altruism. Using data from the German SocioEconomic Panel Study, we find that public sector employees are significantly more altruistic and lazy than observationally equivalent private sector employees. A series of robustness checks show that these patterns are stronger among higher educated workers; that the sorting of altruistic people to the public sector takes place only within the caring industries; and that the difference in altruism is already present at the start of people's career, while the difference in laziness is only present for employees with sufficiently long work experience."
"Working for a Good Cause" by Robert Dur and Robin Zoutenbier (May 15, 2013, CESifo Working Paper Series No. 4227: http://ssrn.com/abstract=2265180)
Abstract: "A rich literature in public administration has shown that public sector employees have stronger altruistic motivations than private sector employees. Recent economic theories stress the importance of mission preferences, and predict that altruistic people sort into the public sector when they subscribe to its mission. This paper uses data from a representative survey among more than 30.000 employees from 50 countries to test this prediction. We find strong evidence for a mutually reinforcing role of altruism and mission alignment in sorting to the public sector, particularly among highly educated workers and among workers in less-developed countries."
"Public Sector Employees: Risk Averse and Altruistic?" by Buurman, Margaretha , Delfgaauw, Josse, Dur, Robert and Van den Bossche, Seth, (June 28, 2012, CESifo Working Paper Series No. 3851: http://ssrn.com/abstract=2094954)
Abstract: "We assess whether public sector employees have a stronger inclination to serve others and are more risk averse than employees in the private sector. A unique feature of our study is that we use revealed rather than stated preferences data. Respondents of a large-scale survey were offered a substantial reward and could choose between a widely redeemable gift certificate, a lottery ticket, or making a donation to a charity. Our analysis shows that public sector employees are significantly less likely to choose the risky option (lottery) and, at the start of their career, significantly more likely to choose the pro-social option (charity). However, when tenure increases, this difference in pro-social inclinations disappears and, later on, even reverses. Further, our results suggest that quite a few public sector employees do not contribute to charity because they feel that they already contribute enough to society at work for too little pay."
Non-scientific polemic based on the above is here: http://opinion.financialpost.com/2013/07/23/william-watson-civil-servants-not-born-lazy-they-learn-it-at-work/
I presume there were no major errors in Excel spreadsheets anywhere around the above studies...