||energy firms from 2008 to<br>2017.|environmental performance, and environmental<br>performance can strengthen the impact of green<br>investment in improving the long-term performance of<br>firms.|
|---|---|---|
|Colombelli et al.<br>(2020)|A market value approach<br>is used on a sample of<br>firms from France,<br>Germany, Italy, the<br>Netherlands, and the UK<br>for 1985-2011.|The stringency of the environmental regulatory framework<br>yields a positive and significant impact, as does the stock<br>of green technologies vis-a-vis non-green technologies.<br>Moreover, the environmental regulatory framework<br>positively moderates the positive effect of the stock of<br>GTs. Also, the quality of firms' knowledge stocks is found<br>to positively influence firms'MV.|
|Hassan (2019)|The natural capital<br>inventory approach is<br>used for 420 energy firms<br>in OECD countries for<br>2013-2016.|<br>Most renewable energy incentive policies deployed in<br>OECD countries stimulate improved accounting-based<br>measures of financial performance. Substituting renewable<br>energy for fossil fuels, incentivized through RE policies,<br>stimulates improved financial performance of energy<br>companies in OECD countries.|
|Przychodzen et al.<br>(2018)|Content analysis is used<br>to corporate disclosures<br>and financial data of 162<br>companies listed on the<br>Frankfurt Stock Exchange<br>for 2007-2016.|<br>Firms with green information technologies are<br>characterized by higher subsequent returns on assets and<br>the market-to-book values of assets ratios. Also, firms<br>introducing green information technology solutions<br>experience permanently lower operating margins and<br>higher costs of goods sold to net sales ratios.|
|Saha et al. (2017)|An optimization and<br>simulation analysis are<br>used.|<br>Continuous investment in green operations and<br>preservation technology can significantly improve the<br>retailer's financial performance. Results also show that the<br>higher price sensitivity of the market always discourages<br>the retailer from investing in green operations. The retailer<br>needs to invest more in green operations for products with<br>relatively high unit value.|
|Gaddy et al. (2017)|A comparison is made<br>between the risk and<br>return profiles of clean<br>energy technology<br>investments against those<br>of other sectors in the<br>USA from 2006 to 2011.|<br>The investment in clean energy technologies<br>underperformed compared to investments in other sectors.<br>Among the clean energy technology investments,<br>investments in companies that develop new hardware,<br>materials, chemistries, or manufacturing processes<br>consumed the most capital and yielded the lowest returns.|

# **6. Conclusions and Final Remarks**

Investments in green and clean technologies are rapidly increasing, particularly in renewable energy and energy-efficient technologies over the last decade. The primary factors behind the growth of green/clean investment are policies and measures introduced by the government in response to environmental concerns, particularly global climate change. The investment is, however, financed mainly by the public sector. The investment is also financed by the private sector, if they are financially incentivized or mandated through regulatory measures. Will the private sector’s engagement continue if there are no financial incentives and regulatory measures? It would if the investment in green/clean technologies reduce production costs and at 39