Every year, Mike Hannigan, a co-founder of the Give Something Back office- supply company, in Oakland, Calif., and his employees calculate how much of the store's previous year's profits they can afford to give to charity. So far, the company has donated about $4-million.

Through a balloting process, the company's customers choose which charities will get 40 percent of the business's donations, employees decide on 30 percent, and Mr. Hannigan and Sean Marx, his business partner and co-founder, decide on the other 30 percent.

You can learn more about the company's approach in a conversation sponsored by The Chronicle and Bolder Giving, an organization that works to encourage philanthropists to give more generously.

Mike Hannigan will be available on Wednesday, August 25, at noon U.S. Eastern time to take questions about how he devised this unusual approach to giving and how others can copy it. Also joining the discussion will be Anne Ellinger, a co-founder of Bolder Giving.

Other discussions in The Chronicle series with Bolder Giving can be found in our discussion archive.