Since leaving office, Gnarr has campaigned for Iceland to abandon its laws regarding traditional Icelandic names, viewing it as discriminatory, e.g. that only some family names are allowed and Gnarr not an approved one. Jón also authored a book entitled "Gnarr!: How I Became the Mayor of a Large City in Iceland and Changed the World". In January 2015 Gnarr joined the Center for Energy and Environmental Research in the Human Sciences (CENHS) at Rice University as their first writer in residence.