Municipal corporations exist in an institutional twilight area, being both private and public, a characteristic, which presumably would be reflected in their choice of accounting standards. The literature of accounting choice does not, however, live in a twilight area, but is fragmented into two main divisions: positive accounting theory (PAT) and institutional theory (IT); only in a very few cases do the theories meet or cross-fertilize. We use both theories in this paper and derive hypotheses from them to explain accounting choices made by municipal corporations. Through testing the hypotheses on a sample of 545 Swedish municipal corporations, we indicate the empirical relevance of both PAT and IT. We conclude by suggesting an integrative approach of PAT and IT in an eclectic alternative. © 2008 Elsevier Ltd. All rights reserved.