I fear I’m in JB MacKinnon’s bad books. Halfway through our Zoom interview, I tilt my camera to adjust to the setting sun — but from this new angle, an e-commerce box can be spotted over my shoulder. Its barcode glows in the fading light, a totem of 21st-century materialism presiding over our call. MacKinnon is too polite to say anything, but he can’t be thrilled by my cardboard companion. After all, the Canadian bestselling author and journalist is on a mission to get us to buy a lot less stuff. The Day the World Stops Shopping, his new book, explores