Despite controversies, sustainability long ago moved from the economy's tributaries into mainstream society.

Sustainability is something of an ambiguous term, but there are several common themes, including: concern for the planet's ecology; taking actions to reduce the risks of global warming; a desire to cut down on waste; worries about the viability of communities; and a focus on generational interdependence. Many people want to live a life and lifestyle that takes sustainability into account.

While researching the topic of sustainability, I came across a short video from the Stanford University Graduate School of Business. The video highlights five insights from the sustainable human behavior course that professors Jennifer Aaker and Szu-chi Huang co-taught.

"The course is focused on how to create a sustainable life, foster healthy relationships and promote a sustainable planet," Aaker said.

The five insights are intriguing. Briefly, they are: Find your multipliers (more on this in a moment); take time to enjoy beautiful experiences (think laughter with friends and family); know your tomatoes (recognize those moments when you and the people around you are working in harmony); act on beauty daily (be mindful of your surroundings); and listen to birdsongs (find a place where you feel aligned with the planet).

The "multiplier" seems especially useful for thinking about personal finances. The multiplier starts with knowing time is our precious resource, the professors said. They encouraged people to think about activities in ways that allow for achieving more than one meaningful goal. (To be clear, this isn't multitasking — far from it).

For example, Aaker does yoga for health and with a friend to strengthen their connection. She volunteers for charity with her daughter, and they spend time together.

"To lead a sustainable life, we need to use time with intent," Aaker said. "Find your multipliers to savor each activity you do and make your life more sustainable."

What's the multiplier when it comes to managing our money? Simply put, frugal is green, and green is frugal. Frugality helps create a financial margin of safety. Households can better withstand setbacks with savings, and they have resources to tap into when opportunities emerge. The embrace of a frugal lifestyle calls for thoughtfulness about purchases, choosing quality rather than quantity, creating less waste and doing more with less.

In other words, the multiplier effect is at work since frugal spending habits support and reinforce everyday efforts to live with a sustainability ethic and practices and vice versa.

Chris Farrell is senior economics contributor for "Marketplace" and a commentator for Minnesota Public Radio.