Den tekniska infrastrukturen i ett land rymmer en rad verksamheter vilka är att betrakta som naturliga monopol. För att hindra att monopolställningen missbrukas har verksamheterna ofta lagts under offentligt huvudmannaskap och regleringar har införts bland annat för att styra prissättningen. Priset regleras vanligtvis genom att avgiftsuttaget måste stå i någon form av relation till kostnaderna för produktionen av varan eller tjänsten. I normalfallet får avgiftsuttaget inte överstiga självkostnaden.

I geografiskt avgränsade monopol kan man genom analys av olika mått skapa jämförande konkurrens i syfte att bevaka effektiviteten. Kostnadsdata är en viktig datadel som ofta används i jämförande mått. För att mått innehållande kostnadsdata skall vara jämförbara krävs det emellertid att redovisningen i de jämförda verksamheterna är likartad och harmoniserad.

I avhandlingen redovisas tre studier som samtliga, om än med olika infallsvinklar, behandlar problem avseende kostnadsredovisning och kostnadsfördelning inom kommunal va-verksamhet. Studierna visar bland annat att de taxor som används inom va-branschen inte på ett relevant sätt speglar förorsakade kostnader på abonnentnivå. Vidare visas att flera av de mått som används i jämförande syfte inte är relevanta, tillförlitliga och jämförbara. Viktiga orsaker är låg grad av harmonisering och olika brister i redovisningen. Flera av de redovisningsprinciper som används leder inte till att redovisningsmodellen blir robust i så mån att jämförbara kostnadsdata redovisas. Dessutom är flera av de uppskattningar och bedömningar som görs tveksamma.

This thesis, which consists of three studies illustrating different angles of approach, discusses problems pertaining to accounting and allocation costs in municipal water and sewage enterprises.

Water and sewage enterprises are financed by charges to users, and are generally run under the auspices of a municipal administration or within the framework of a municipal company. User fees are regulated by water and sewage law, which stipulates that these charges may not exceed what is necessary to cover the essential costs of the service. However, this only applies at an aggregate level, and the law says nothing about how the charges are to be divided between subscribers. It is true that the water and sewage law states that “the fees charged the subscribers are to be apportioned on a reasonable and fair basis.” This is regarded as manifesting the principle, set forth in the municipal act, that all citizens should be treated equally. Opinions vary as to how this principle is to be interpreted.

Water and sewage enterprises characteristically operate as geographically delimited monopolies. By analyzing various key data and thereby comparing the performance of various water and sewage enterprises, it is possible to survey the efficiency of this type of natural monopoly. However such comparisons require that there be standard measures by means of which comparisons can be made. Cost data are valuable, and often serve as key data in comparative measures. For cost data to be comparable, it is essential that accounting in the enterprises compared be similar and harmonized.

The studies shows that the rates charged by water and sewage businesses are too aggregated, and do not reflect actual user-level costs in a relevant way. Several performance measures used in the business for benchmarking and comparisons could also be criticized: these measures are also overly aggregated, and do not capture and describe the most important events and causes.

Even if the performance measures were designed to be more adequate it would still be difficult to make relevant and reliable comparisons between various water and sewage enterprises, unless the accounting is reconstructed and made comparable. At least, this is true when it comes to measures containing accounting data, such as productivity and efficiency measures. Studies show that currently available accounting data is not comparable, and therefore cannot be regarded as relevant and reliable. The level of harmonization is low for accounting in this field, and several of the accounting principles applied do not lead to a robust accounting model that produce data that is comparable. The studies show that three criteria must be fulfilled for accounting data to be comparable: (i) accounting must be harmonized; (ii) applied accounting principles must lead to robustness of the accounting model (iii) the principles must be used correctly, in a true and fair way.