The Heartland Institute is a 501(c)(3)
What is the purpose of a 501(c)(3)?
Qualifying Purposes
In order to qualify for 501(c)(3) status, an entity must be organized and operated exclusively for religious, charitable, scientific, testing for public safety, literary, or educational purposes, or to foster national or international amateur sports competition, or for the prevention of cruelty to children or animals.
http://www.501c3.org/what-is-a-501c3/
What is the Heartland Institute and is it really a 501(c)(3)?
Mission: Its mission is to discover, develop, and promote free-market solutions to social and economic problems.
Funding: Approximately 5,300 supporters contribute to an annual budget of $6 million. Heartland does not accept government funding. Contributions are tax-deductible under Section 501(c)(3) of the Internal Revenue Code.
https://giving.heartland.org/about
One example of a Heartland institute "free-market solution to social and economic problems":