Dear economist - my housemates won't clean

Dear Economist,

I am an economics student sharing a house with two other students and there is an issue with keeping the kitchen clean. I thought that a grim punishment strategy would maintain a system of alternate cleaners. But my threat to “punish” by refusing to clean indefinitely is not seen as credible by my housemates as I value a clean kitchen more than they do. What to do?

Tom, Gloucestershire

Tim Harford's answer is here.