Nothin was chairman of about 20 committees and expert investigations, including the Committee on the "Hovrätterna" ("Kommittén angående hovrätterna") in 1926, "Dalautredningen" from 1930 to 1932, "Statens organisationsnämnd" ("National Organization Board") until 1932, Aviation Investigation of 1934 ("1934 års luftfartsutredning"), the "Mother Investigation" of 1935 ("1935 års "mammututredning"") and the Municipal Tax Preparation of 1936 ("1936 års kommunalskatteberedning"), and various negotiating delegations between the Crown and the City of Stockholm.