Are we running out of resources? That’s been a hotly debated question since the publication of Paul Ehrlich’s The Population Bomb in 1968. The Stanford University biologist warned that population growth would result in the exhaustion of resources and a global catastrophe. University of Maryland economist Julian Simon, in contrast, argued that humans would innovate their way out of resource shortages. He believed that people were the “ultimate resource” that would make other resources more plentiful.