Purpose: The objective of this article is to understand how to optimize partnerships between the public and business sectors. It aims to use a reference group influence model to help identify which kinds of public services are best suited to this type of collaboration. Design/methodology/approach: Consumer data were collected in two stages using surveys. Data were analyzed using two-sided paired t-tests and a mixed factorial MANOVA. The model is validated in the two largest Hispanic consumer markets - Mexico and Spain. Findings: The paper finds that reference group influence has a greater impact on brand decisions for publicly consumed public services, and on service decisions for public services for which consumers pay extra. Reference group influence varies between contexts/countries. Research limitations/implications: Despite the economic, development and cultural differences between Mexico and Spain, countries with even greater differences, or additional countries, could have been included in the study. Although commonly accepted for theory testing and reference group research, the use of a student sample during the second stage of this study limits the extendibility and generalization of the results. Originality/value: Decision-making shortcuts have been studied for years by behavioral scientists. However, to the authors' knowledge no research has explored how reference group influence affects public service consumption, and this understanding leads to the optimization of public-private collaborations.