Do University-Industry co-publication volumes correspond with university funding from business firms?

Analysts of university-industry interaction sometimes measure it through numbers of university-industry co-publications (UICs), because of their relative availability and international comparability. However, we do not know whether UICs correspond to a more direct measure of interaction: university funding from firms. We propose a conceptual model on four types of relationships between UICs and university funding from firms, emphasising the interactive nature of their relation. We test the model with UIC and income data from the Polytechnic University of Valencia at individual level: around 6-7% of researchers participating in projects with firms were authors of UICs published in 2008-2011; and around 27% of those UIC authors were participating in projects with firms during that period. Overall, we do not find evidence of any significant positive correlation between UIC output and university funding from the business sector in general. The one exception is a minority of authors who participate in business-funded projects, where we found a positive association of current UICs and business funding.