I was asked to share some resources on sludge and am doing this here. This is a somewhat random list. I use this as well to summarize our own work on sludge, mainly in the context of environmental policy making, so please excuse the bias to our work in the below list.

If you are interested in working on sludge, please get in touch (l.k.lades@stir.ac.uk). I am particularly keen on exploring opportunities for developing grant applications on sludge.

What is “sludge”? In behavioural science, sludge describes unnecessary frictions that make it harder for us to do what we want to do. Administrative burdens are a form of sludge in the context of interactions between citizens and the state.

Applied/Policy documents

• Lades, L., Johnson, J., & O’Connor, R. “Sludge” in Irish Policymaking.
• Lentz, P., Augustenborg, C. & Lades, L., (2025). Reducing administrative frictions in Ireland’s afforestation scheme. PublicPolicy.ie
• Lentz, P., Augustenborg, C., Lades, L., & Martin (2025). Improving engagement with Ireland’s solar schools scheme by reducing administrative frictions. PublicPolicy.ie
• Lentz, P., Augustenborg, C. & Lades, L., (2025). Administrative frictions in Ireland’s Shared Island Sports Club EV Charging Scheme. PublicPolicy.ie
• NSW Behavioural Insights Unit. (2024). The NSW Government Sludge Audit Method Guide.
• OECD. (2024). Fixing frictions: ‘Sludge audits’ around the world.
• OIRA. (2024). Tackling the Time Tax: Making Important Government Benefits and Programs Easier to Access.
• …

Academic papers

• Christensen, J., Aarøe, L., Baekgaard, M., Herd, P., & Moynihan, D. P. (2020). Human capital and administrative burden: The role of cognitive resources in citizen‐state interactions. Public Administration Review, 80(1), 127-136.
• Grieder, M., Kistler, D., & Schmitz, J. (2022). How sludge impairs the effectiveness of policy programs: a field experiment with SMEs. Behavioural Public Policy, 1-9.
• Herd, P., & Moynihan, D. P. (2019). Administrative burden: Policymaking by other means. Russell Sage Foundation.
• Lades, L., Lentz, P., & Augustenborg, C. (2025). Administrative Burdens as Barriers to Afforestation: A Sludge Audit of Ireland’s Afforestation Scheme (No. 8xg2e_v1). Center for Open Science.
• Lades, L. K., Clinch, J. P., & Kelly, J. A. (2021). Maybe tomorrow: How burdens and biases impede energy-efficiency investments. Energy Research & Social Science, 78, 102154.
• Madsen, J. K., Mikkelsen, K. S., & Moynihan, D. P. (2022). Burdens, sludge, ordeals, red tape, oh my!: a user’s guide to the study of frictions. Public Administration, 100(2), 375-393.
• Martin, L., Delaney, L., & Doyle, O. (2024). Everyday administrative burdens and inequality. Public Administration Review, 84(4), 660-673.
• Samahita, M., & Lades, L. (2023). Compliance Spending Aversion: An Unintended Consequence of Charity Regulation. Journal of Behavioral Public Administration, 6.
• Shahab, S., & Lades, L. K. (2024). Sludge and transaction costs. Behavioural Public Policy, 8(2), 327-348.
• Shreedhar, G., Moran, C., & Mills, S. (2024). Sticky brown sludge everywhere: can sludge explain barriers to green behaviour?. Behavioural Public Policy, 8(4), 701-716.
• Soman, D., Cowen, D., Kannan, N., & Feng, B. (2019). Seeing sludge: Towards a dashboard to help organizations recognize impedance to end-user decisions and action.
• Sunstein, C. R. (2021). Sludge: What stops us from getting things done and what to do about it. MIT Press.
• Sunstein, C. R. (2022). Sludge audits. Behavioural Public Policy, 6(4), 654-673.
• Thaler, R. H. (2018). Nudge, not sludge. Science, 361(6401), 431-431.
• …

A new OECD report is also in the making. They gather insights from a global sludge expert panel (on which I am sitting) to develop a unified way of measuring sludge. This is really exciting.

Some might have seen on LinkedIn that we hosted an Irish EPA-funded Workshop on “Sludge and Administrative Burden” in Dublin, Ireland, on May 08, 2025. This workshop was part of the ABICAP project funded by the EPA. It was organised by researchers from UCD Environmental Policy, UCD Behavioural Science and Policy, and us at the Stirling Behavioural Science Centre in association with the Irish Behavioural Science and Policy Network (IBSPN). It will be free for participants to attend. We brought together behavioural scientists, public administration scholars, policymakers, and other stakeholders to discuss newest developments on sludge and administrative burden. Below is the schedule.

Schedule (Thursday, May 08, 2025):

9:30 AM – 9:45 AM: Welcome and Introductions

9:45 AM – 10:15 AM: Patricia Lentz (UCD) – From Policy to Practice: Administrative Challenges in Ireland’s Climate Transition. (1/2)

10:15 AM – 10:45 AM: Cara Augustenborg (UCD) – From Policy to Practice: Administrative Challenges in Ireland’s Climate Transition. (2/2)

10:45 AM – 11:15 AM: Coffee Break

11:15 AM – 11:45 AM: Elena Achtypi (HMRC) – Sludge Audits at HMRC

11:45 AM – 12:15 PM: Lucie Martin (ESRI) – Sludge in Accessing Benefits During Ireland’s Cost-of-Living Crisis

12:15 PM – 12:45 PM: Robert Murphy (Department of Health) – Reducing Sludge to Improve Access to Healthcare

12:45 PM – 1:45 PM: Lunch

1:45 PM – 2:15 PM: Leonhard Lades (Stirling / UCD) – Vulnerability to Different Types of Sludge: Evidence from Ireland

2:15 PM – 2:45 PM: Glenn McNamara (UCD) – Who is Most Influenced By Sludge? Experimental Evidence

2:45 PM – 3:15 PM: Coffee Break

3:15 PM – 4:00 PM: Eva Koromilas (NSW / OECD): The Global Sludge Expert Panel

4:00 PM – 4:30 PM: Q&A Panel