Limitations and suggestions for future research
Even though this dissertation uses a multitude of approaches and data foundations a number of limitations to the results exist: The main focus lies on alternative investments in the clean technology and renewable energy industries. Thus the applicability to other industries may be limited due to peculiarity of this focus. Chapter 2 and 5 observe solely VC investments, chapter 4 only asset finance thus limiting transferability to other alternative asset classes or even different settings in financial markets. Similar, the focus on RE in chapter 4 and on solar energy and fuel cell technology in chapter 5 might limit general applicability. Furthermore regional settings, on the global level in chapter 2, comparing the USA and Germany in chapter 3, OECD country focus in chapter 4, and US industries in chapter 5 might impede comparability and transferability.
Methodological limitations regarding the approaches used occur as well in the studies. Quantitative content analysis has to face limitations inherent to the approach. Selection of analyzed data exposes the analysis to possible biases. In the case of chapter 2 and chapter 5, newspaper articles are the textual foundation. A broad selection and large quantities of data support the independence from researchers’ expectations. Furthermore dictionary development can be influenced by the researcher and thus have to precede in a careful manner. A structured deductive approach, as used in both studies, prevents problems.(Elo & Kyngas, 2007; Hsieh & Shannon, 2005). Similar the qualitative nature of chapter 3 leads to limitations with interview partner sampling, coding, and interpretation of results (K. Eisenhardt, 1989; Jick, 1979). Chapter 4 uses policy dummy variables and thus cannot differentiate between different policy characteristics (Bergek et al., 2013b; Jenner et al., 2013; Muller et al., 2011).
Based on the limitations of these studies, future research avenues open up. Not only could the results be tested in different industries or asset classes, regional settings and on different time frames, it would furthermore be advisable to confirm the findings in a more quantitative setting. In addition, research to test the complex interactions and interdependencies between finance, innovation, and, policy thus demand different methodological approaches. The emergence of investment categories and the role of finance in industry development offers various research opportunities. The transfer to other industries and detailed case studies would be interesting research. Comparing different evolutionary developments like cleantech to software or to biotech would be advisable to understand innovation accelerating conditions (Audretsch, 1995; Avnimelech & Teubal, 2006; O’Sullivan, 2005). The role of finance in innovation should get explored furthermore as well. The relationships between investors and their respective investors and the influence on innovation offers many opportunities to explore. How sustainability efforts of pension funds could possibly help to steer the sustainability transition is an interesting question for example (Bergek & Onufrey, 2013; Mary Jean Burer & Wustenhagen, 2008; Farla et al., 2012; Lovio et al., 2011).
Future studies could look at the influence of policies on the diffusion of RE in different settings. Extending this research regionally could help to look at differences in emerging and developing countries. Additionally interesting would the effects of policy on niche technologies be, which will get more important in the future. Wave and tide as well as off-shore wind energy might be interesting subjects. Furthermore, interaction effects between the different policy instruments are worthwhile investigating in a longitudinal research design to discover complementarities and synergies (Bergek et al., 2013a; Jenner et al., 2013; Luthi & Wustenhagen, 2012b; Muller et al., 2011).
This dissertation contributes to the research debate on how to accelerate green innovation and as well on the role of finance and policy in the clean technology innovation chain. Furthermore it adds some implications for investors, innovators, and policy makers. Hopefully, academic and industry stakeholders can utilize this work and build on the findings. As innovation in clean technologies is key to green growth, it is advisable to accelerate green innovation.