On Monday, the Worldometers clock, which rapidly ticks off the ever-increasing number of humans inhabiting our planet, leapt across the seven-billion mark. In honor of the staggering sum (and with a hat tip to Harper’s), let’s look at some other numbers relating to population.

• Cost of raising a child, birth to age eighteen, excluding college, for a middle-income, two-parent family in the United States as of 2010: $226,920 [Read more…]