After Charles Mann, the National Academies Communication Award-winning author of 1491and 1493, gives an intricate, gripping account of the elaborate methods Chinese farmers must undertake in order to grow sweet potatoes, I realize my grandfather and I must have some kind of psychic connection.

ODU’s 2013 Literary Festival is the fourth consecutive festival I have attended with Grandpa in tow. A retired but renowned economist and always an avid reader, Grandpa has, for the last several years, suffered from macular degeneration. It’s to the point that now, he can no longer even read large-print text. Attending these events puts him back in touch with reading. The events he has attended have ranged from poetry to fiction to music to, now, nonfiction. I never know what will catch his attention. At the end of any event he might turn to me and say, “That was interesting!” or “I don’t know if I liked that.”

But I do know that he perks up Pavlov-ways at the word “economics.”

The moment Mann begins detailing the financial, social, and political implications of relocating entire Chinese villages to the desert west of the country to terrace dunes for sweet potato farming—and reconstructing those terraces after any rainfall—I know that his penetrating analysis of globalization as centered on something as small as the sweet potato will snatch Grandpa by the glasses and lift his hand into the air come Q & A time. When I glance over at him to confirm, I find him leaning in, rubbing at his chin. I wonder whether he’s thinking the same thing I am about those potatoes.

Once Mann finishes and starts taking questions, Grandpa raises his hand. He waits. He is as patient with the Q & A session as he ever was with me or my cousins or, I would wager anything, my mother. His gentle hand is never called, his question left unasked. But I have to know, so as we leave, I ask him, “Grandpa, what were you going to ask?”

“How much one of those potatoes costs,” he replies.

-Natasha Arnold