Start-ups and scale-ups often make outsized contributions to innovation and job creation. However, while entrepreneurial ecosystems in countries and regions are increasingly studied, less is known about differences by sector. What role do start-ups and scale-ups play in the development of different future growth sectors? What problems and bottlenecks does government policy need to address? To what extent do the start-up and scale-up contributions and obstacles vary by sector, and what is in common across sectors? This report examines the entrepreneurial ecosystems of three of Denmark's sector strongholds, sectors where future growth is likely to be generated - advanced production, energy technology and food and bio resources. A focus on Denmark includes the scale and nature of start-ups and scale-ups in different sectors, the bottlenecks, the current policies and how they can be refined. In addition, nine international policy experiences are presented as inspiring practices for Denmark and other countries - covering Austria, Canada, Finland, Ireland, the Netherlands, Norway, Sweden, the United Kingdom, and the United States. Recommendations are offered for Denmark across areas such as entrepreneurial finance, networks, public procurement, and cluster management organisations, covering both cross-sector and sector-specific recommendations.