Design for the Other 90 Percent

"Design for the Other 90 Percent," covers the topic of design for poor populations [source: Smithsonian]. Martin Fisher, a mechanical engineer who worked on development projects in Kenya for more than 17 years, contributed an essay describing his design principles for the poor. Here are the first few.
Does the Slingshot meet them?

• The top need of people who are poor is to make money. The device should help someone make money on the local market.
• People who are poor don't lack time and labor, so unless they can make money from the saved time and labor, they won't buy the device.
• A device should pay for itself in "farm time" -- three to six months.
• Successful devices address people's true needs rather than what "we" think "they" need.

Fisher adds that if a device won't make someone an immediate profit but will save money, it shouldn't sell for more than the cost of a chicken at the local market. A chicken, like this device, is an affordable, occasional luxury for poor families. But if the device costs more, only the middle class will buy it, and this group already has money for its basic needs [source: Fisher].
While Fisher's principles are reasonable for many product designs developed for poorer populations -- the LifeStraw certainly fits some of these criteria -- they don't seem applicable to the Slingshot in that it's a system that will provide for a large population, rather than an individual. And, while it's easy to agree with Fisher's statement that poor people need to make money, there's one caveat to consider; is it truly their "top" need? It's likely many would argue that access to clean drinking water demands top billing.