The Burning Glass Institute, Harvard Business School's Managing the Future of Work Project, and the Schultz Family Foundation have partnered to create the American Opportunity Index. This first-of-its-kind scorecard ranks companies by how well they create upward mobility for their employees.

The index aims to give workers the tools they need to make the best decisions in their job searches. It assesses the 250 largest US public companies based on the experience of more than 3 million employees. However, what sets the index apart is its focus: worker outcomes as opposed to corporate policies or practices.

The need for such an index comes from the downward trend of upward mobility in the US workforce. "Opportunity and upward mobility have long been central to the American experiment, however, this generational trend has been on a decades-long downward slide. If you were born in the 1940s, you had a 90 percent chance of doing better than your parents. Today, it's even odds," says Matt Sigelman, president of the Burning Glass Institute.

The index is especially important for workers without degrees, because it measures which companies are most likely to create opportunities in roles open to noncollege graduates in terms of wage, access, and mobility.