New census figures bolster claims made in the past few years that China is suffering from a demographic problem of a different sort: too low a birth rate. The latest numbers, released on April 28th and based on the nationwide census conducted last year, show a total population for mainland China of 1.34 billion. They also reveal a steep decline in the average annual population growth rate, down to 0.57% in 2000-10, half the rate of 1.07% in the previous decade. The data imply that the total fertility rate, which is the number of children a woman of child-bearing age can expect to have, on average, during her lifetime, may now be just 1.4, far below the “replacement rate” of 2.1, which eventually leads to the population stabilising.