Minneapolis economist Rob Grunewald is known for the influential paper he co-authored a decade ago showing that public investments in structured early childhood education have enormous economic payoffs down the line. But on Tuesday, when he accepted an award for his advocacy of early childhood education, Grunewald took a tangent when he stressed the value of also getting children outside for more unstructured time to explore and create.

Citing a book called the Coyotes Guide to Connecting with Nature, Grunewald said children need more unstructured time outside to run and hide and explore and "play in the dirt."

"The outdoors is a natural classroom for childhood development. But children today ... don't get to spend enough time outdoors " said Grunewald, an economist from the Federal Reserve Bank in Minneapolis. He received an award Tuesday from a local advocacy group known as the Start Early Funders Coalition for Children & Minnesota's Future. The event was held at the Science Museum of Minnesota.

Grunewald doesn't have children but said the value of getting kids outdoors was passed to him by his grandparents, who took him camping for days when he was only six years old. The Coyote book is filled with ways to explore the outdoors and play games that foster creativity and a connection to the natural world. (The ideas obviously differentiate from the structured time that many children experience outdoors through school and club sports.)

"When you get outdoors, there are so many sensory experiences that are available to you," he said.