Economist Tyler Cowen, who writes the Marginal Revolution blog with fellow economist Alex Tabarrok and hosts the long-running interview series Conversations with Tyler, has announced that his next Conversation will feature Roman Mars, the American radio producer best known for the design-focused podcast 99% Invisible. Cowen is inviting readers to suggest what he should ask, a recurring feature of the series, which releases long-form interviews with guests drawn largely from economics, technology, policy, and the arts as podcast episodes accompanied by transcripts.

"Most of all he is obsessed with design," Cowen writes of his guest, introducing him with a Wikipedia excerpt:

Roman Mars is an American radio producer. He is the host and producer of 99% Invisible, a KALW radio show and podcast, and a founder of the podcast collective Radiotopia, which he describes as efforts "to broaden the radio landscape [and] make shows that aren't bound by conventions" of public radio in the United States. In 2020, he co-authored the New York Times best seller The 99% Invisible City with Kurt Kohlstedt…Mars, with Elizabeth Joh, also hosts the podcast What Roman Mars Can Learn About Con Law.

The excerpt touches on several widely recognized landmarks of Mars's career. 99% Invisible, which launched in 2010, explores the often-overlooked architecture and design that shape everyday life, airs on San Francisco public radio station KALW, and has grown into one of the best-known podcasts about design. In its early years the show financed its expansion through Kickstarter campaigns that ranked among the platform's most successful journalism projects, an early high-profile example of listeners directly funding a podcast's growth. Radiotopia, the podcast collective Mars founded, debuted in 2014 under the stewardship of the public media organization PRX and pools cross-promotion and listener support to help sustain independent shows. The 99% Invisible City, his 2020 book co-written with Kurt Kohlstedt, became a New York Times best seller. What Roman Mars Can Learn About Con Law, co-hosted with law professor Elizabeth Joh, applies constitutional law to current events.

Cowen also directs readers to Mars's TED talk on city flags as "a good introduction to his thought." The widely viewed talk, delivered at TED2015 and titled "Why city flags may be the worst-designed thing you've never noticed," examines principles of good design through the example of municipal flags, including Mars's well-known critique of the design of many American city flags and his affection for well-designed ones.

"So what should I ask him?" Cowen asks, closing his post with an open call for reader-submitted questions ahead of the interview. Once released, the conversation will join the Conversations with Tyler archive, where past episodes are available with full transcripts.

The announcement was published on Marginal Revolution on August 17, 2026. Original post: What should I ask Roman Mars?