title: The Great Recession of 2007 in the United States and the male: female ratio at birth.
abstract: OBJECTIVE
  Male live births slightly exceed female live births by approximately 3%. The ratio of male to total live births is conventionally represented as M/F. Many factors have been shown to affect M/F, mainly privation, toxins, and stress, all of which reduce M/F. Population stress may be engendered by natural phenomena such as earthquakes and man-made events such as short wars, terrorist attacks, and contracting economies. This study was conducted to ascertain whether the onset of the "Great Recession" (2007) was associated with changes in M/F in the United States (US).
  
  
  METHODS
  Annual monthly live births by gender for January 2006 to December 2008 were obtained from United States Centres for Disease Control and Prevention.
  
  
  RESULTS
  In 2007, there were 4316233 live births [M/F: 0.51157; 95% confidence intervals: 0.51110-0.51205). M/F rose between January and June, and then fell sharply between August and December. M/F was statistically significantly lower in the second half of 2007 (p=0.007). The dip in M/F from June to July was also significant (p=0.02). These findings were not replicated in the amalgamated data for 2006 and 2008.
  
  
  CONCLUSIONS
  The United States housing boom of the mid-2000s was fueled by rising house prices and cheap mortgages given to credit-poor buyers. A halt in rising house prices resulted in defaults and foreclosures, triggering the worst financial crisis since the Great Depression. The associated stress appears to have decreased M/F in the US.
authors.affiliation: Department of Paediatrics, Mater Dei Hospital, Tal-Qroqq, Malta.
authors.forename: Victor
authors.initials: V
authors.lastname: Grech
keywords: United States; birth rate/trends; economic recession; infant; newborn; sex ratio