A paper I coauthored with the Mercatus Center's Susan Dudley on the history of the regulation of silica dust and the problems regulators face in defining exactly what it is they are regulating is available on SSRN. Silica is a big component in cat litter (hence the header) and some feared that the hazards of silicosis would result in skull & crossbones warnings on bags of cat litter. By posting about it here, I hope to drive up my downloads, and hence enhance Case's academic reputation through a higher SSRN ranking. Thus I am actually posting on my assigned topics.