As you may have noticed, my productivity has decreased noticeably since last summer. This is not due to lack of interest. No, this is due to lack of sleep. I have a teenager who should be going to his first period class around 9am but instead is learning trigonometry at 7:20. He has a mom who should be sleeping until 7am but is awakened over an hour before her body would like to see the light of day. All work and no sleep has made me a tired and unproductive writer. I was once asked if I am an early bird or a night owl. "Neither," was my reply. "I am a wimp at both ends." Always have been and always will, I suspect. And so my ears perked up last week while listening to an interview with Jennifer Senior , contributing editor at New York magazine and author of a new book on parenting called All Joy and No Fun: The Paradox of Modern Parenting . Kids, she points out, were originally part of the economic engine of a family; they were housed and fed and expected to wor