The existing literature proposes a broad spectrum of methodologies to measure firm's superior operating capabilities, referring to them under different names such as 'knowledge assets', 'intellectual capital', 'organisation capital', etc. Through the work reported in this thesis, I intend to contribute to the research field by exploring one specific measure of a firm's operating capabilities proposed by Lev, Radhakrishnan and Zhang (Abacus, 2009). These researchers empirically construct an organisation capital measure and argue it has predictive ability for future performance and is able to explain future abnormal stock returns in the USA. I extend their research to the UK. In doing so, I also critically discuss the organisation capital estimation process and propose potential improvements to the technique. I find evidence of its construct validity in the UK. I examine the organisation capital measure's predictive ability for future performance. The results suggest that this measure is positively associated with future sales growth in the UK. Additionally, the organisation capital measure seems to explain persistence of the operating income and sales of firms in the UK. Via value relevance tests, I obtain empirical evidence that the organisation capital measure is positively associated with equity market value in the UK. Moreover, it is positively associated with the earnings multiplier in value relevance tests. This finding is consistent with empirical evidence that the organisation capital measure is positively associated with one-year ahead earnings and positively affects earnings persistence in such an association in the UK. Finally, I fail to find evidence of the organisation capital measure's ability to explain future excess stock returns in the UK. This suggests that information on firm-specific operating capabilities captured by the organisation capital measure is recognised by the capital market participants and contemporaneously incorporated into stock prices. This result, however, contrasts with the Lev et al. (2009) findings in the USA that organisation capital is mispriced.