On the carbon premium in Swiss stock returns

This paper evaluates whether CO2 emission levels or emission intensities are firm characteristics that drive Swiss firms’ stock returns. We show that standard characteristics such as size and the book-to-market equity ratio are more important determinants of firm-level stock returns than are CO2 levels (intensities). Brown firms (high CO2 levels or intensities) tend to be large and exhibit low book-to-market equity ratios, whereas their green counterparts are small and exhibit high book-to-market equity ratios. This explains why return differences between brown and green firms are statistically indistinguishable from zero after controlling for exposures to standard risk factors.