Dr. Paul Polak, a former psychiatrist who became an entrepreneur and an inventor with a focus on helping the world’s poorest people create profitable small businesses, died on Oct. 10 in Denver . He was 86.

His daughter Kathryn Polak said the cause was heart failure. Dr. Polak lived in Golden, Colo.

In an era when foreign aid is largely based on charity , Dr. Polak (pronounced POLE-ack) instead advocated training people to earn livings by selling their neighbors basic necessities like clean water, charcoal, a ride in a donkey cart or enough electricity to charge a cellphone.

Although the nonprofit companies he created did accept donations, their purpose was to help poor people make money. His target market was the 700 million people around the world surviving on less than $2 a day , and he traveled all over the world seeking them out.

Before embarking on any project, said Dr. Polak would interview dozens of villagers.

“I’ve interviewed over 3,000 families,” he said in 2011. “I spend about six hours a day with each one — walking with them through their fields, asking them what they had for breakfast, how far their kids walk to school, what they feed their dog, what all their sources of income are. This is not rocket science. Any businessman knows this: You’ve got to talk to your customers.”