When it comes to building purpose-driven brands, Elon Musk is something of a pioneer. Musk's electric car company, Tesla, and his aerospace manufacturing business, SpaceX, both ranked among the most purposeful brands in America, according to a new study.

Published by the marketing and advertising agency StrawberryFrog and corporate reputation management company RepTrak, the 2021 Purpose Power Index is based on a survey of more than 6,500 respondents about more than 200 brands. The companies revealed the list of the 20 most purposeful brands during Inc.'s Purpose Power Summit 2021 stream event on Tuesday, with Musk's SpaceX claiming the No. 3 spot, and Tesla ranking No. 9.

Ecofriendly cleaning and personal care company Seventh Generation was the most purposeful company on the list, followed at No. 2 by the shoe and apparel company Toms. Conducted in January, the study measured corporate brand purpose using an algorithm that looked at four main elements: standing for more than just making money; improving the lives of people and communities; benefiting society as a whole; and changing the world for the better. 

The study found that the link between a company's reputation and its purpose has grown stronger since the most recent Purpose Power Index, published in 2019. 

"The integrity of purpose matters more than ever before and has a bigger impact on the overall reputation of your organization," Stephen Hahn-Griffiths, RepTrak's global executive vice president of reputation intelligence and enterprise growth, said in a presentation at the Purpose Power Summit. Hahn-Griffiths added that more than half of the top 20 companies on this year's list are new to the top 20, and are not companies that were founded with any social mission in mind. "[They've] risen through the lens of being purposeful, but aren't necessarily companies born out of purpose," he said.

Chip Walker, head of strategy at StrawberryFrog, noted that this year's most purposeful brands consisted of a much more varied group of companies than in 2019, resulting from both what he called "bold innovation" and a response to the Covid-19 pandemic. Pharmaceutical companies such as Pfizer, ranked at No. 188 in 2019, for example, rose to No. 49 after having developed a Covid-19 vaccine in record time. 

The top 20 most purposeful brands from the 2021 report are:

1. Seventh Generation

2. Toms

3. SpaceX

4. GSK

5. Abbvie

6. Kimberly-Clark

7. Allbirds

8. 3M

9. Tesla

10. Genentech

11. Clorox

12. USAA

13. Stonyfield Organic

14. Intel

15. LG Corp

16. REI

17. Zoom

18. Kellogg's

19. Vermont Creamery

20. Etsy