It is said that one of the most widely-read newspaper sections in New York City is the obituary page, due to people eager to get into rent-controlled apartments that tenants refuse to give up - until death. While this is meant to be an amusing anecdote, death is a sad but inescapable fact of life, and it creates housing changes. A survey of home buyers has consistently ranked changes in family circumstances as one of the top reasons for buying a home.
The number of deaths in the United States has remained steady at 2.4 million per year for the past 10 years. Interestingly, there is a seasonality in death statistics, with more people dying in January, February, and March (213,000 deaths per month on average) and fewer dying in July, August, and September (193,000 per month on average). The 20,000 difference, representing a 10% change, cannot be all attributed to fewer days-in-a-month in February alone (which would imply only a 2% gap).
As for live births, these also causes family changes and there is also a seasonal pattern visible here. There are more births in July, August, and September compared to January, February, and March, by an 8% gap (more than the 2% gap that would be accounted for by fewer days in February).
One generally thinks of slower home sales in winter months due to weather, but there may also be other factors at work holding back home sales in January, February, and March.