International Paper, the largest cardboard box manufacturer in the United States, recently closed two mills in Georgia and cut more than a thousand jobs. While this might look like routine cost-cutting in a tired industrial sector, it may actually be a warning light for the broader economy. The cardboard box industry has long served as a barometer to measure real-world demand. Everything from big appliances to frozen pizzas is shipped in these boxes. When factories ramp up and businesses expect higher sal ...