Sunday, October 30, 2016

Halloween Fun

Happy Halloween!

Normal Distribution vs. Paranormal Distribution
Source: Journal of Epidemiology and Community Health


There were an estimated 41.1 million potential trick-or-treaters (children age 5-14*) in the United States in 2015, roughly the same as in 2014.

But Halloween is clearly not just a children's holiday. 171 million Americans of all ages will be celebrating Halloween this year (up nearly 10% from last year), with total spending reaching more than $8.4 billion.

The average American adult will spend $83 on decorations, costumes and candy, up considerably from $74 last year, and above the previous peak of $80 per person in 2012.

For those who will dress up to celebrate the holiday:
The most popular children's costume: Superhero! (knocking princess from the top spot after an 11-year reign).

Sources: National Retail Federation and U.S. Census Bureau, Facts for Features
*Note: Of course, many other children - older than 14, and younger than 5 - also go trick-or-treating.


America's candy consumption in 2010 was nearly 25 pounds per person. If this candy were entirely Snickers bars, it would be the equivalent of nearly 4 candy bars, per week, per person. The volume of candy consumed, much like home prices, peaked in the middle of the decade, dipped at the start of the recession in 2008, and increased slowly each year since then. Another scary fact is that 2010 is the last year for which we'll have this data. Budget cuts led to the termination of the Current Industrial Reporting program.

American confectionery manufacturers produce about 35 million pounds of candy corn each year. That adds up to 9 billion candy corns - or about 30 kernels per person in the U.S.

For Halloween itself, Americans purchase nearly 600 million pounds of candy, spending nearly $2.6 billion for treats to hand out to trick-or-treaters.

Sources: U.S. Census Bureau, Current Industrial Reports, Confectionery: 2010National Confectioners AssociationDaily Infographic 2011 and 2012

Friday, June 3, 2016

2015 data show historic low teen births, rising birth rate at older ages

Highlights from the preliminary 2015 birth data

Teen and early 20-something births are at (another) all-time low in the U.S., and birth rates continue to rise at ages 30 and older.

As a historical demographer, who has some experience with fertility and mortality rate trends over the past century (and the century before), and I can say with conviction that the trend is not really new. Birth rates for women ages 35 and older are not higher now than ever. They're not even higher now than they were in the 1950s and 1960s.

The National Vital Statistics Reports, published by the U.S. Centers for Disease Control and Prevention, provide historical birth rate data by age of mother as far back as 1970. Earlier data must be compiled from a variety of other sources including the older, and often PDF-scan-only Monthly Vital Statistics Reports and the U.S. Statistical Abstract.

From those sources I collected data as far back as 1920, with complete annual data from 1935-present. The historical birth rates (births per 1,000 women) are shown in the chart below.

Zeroing in on ages 35 and older, to show more detail on the chart scale, we see that birth rates are indeed higher in 2015 than they were in 1970. But we do not need to go back very much farther to find a time at which birth rates were higher than they are today: In the 1960s birth rates were higher for all ages 35-49 than they were in 2015.

If we go as far back as 1920, birth rates were nearly five times higher for women ages 45-49 than in 2015, nearly three times higher for ages 40-44, and fifty percent higher for ages 35-39 than they are at present.

In short, the phenomenon of increasing birth rates for women in their 30s and 40s is as much a return to historical patterns as a deviation from them.

To be clear, some pregnancy risks do increase with advanced maternal age:
"older age strongly increases a woman's chances of at least three untoward outcomes—namely, stillbirth, miscarriage, and ectopic pregnancy" (Stein and Susser 2000)
However, there is considerable evidence that socio-economic factors play the most important role in birth outcome - perhaps far outweighing the age effects (Cohen 2012, Azimi and Lotfi 2011, Stein and Susser 2000).

As for the current focus on trends in the past four decades, I suspect the ease of collecting data from 1970-present is partly the cause of the focus on a "huge" increase in childbearing at older ages... when, in reality, rates have fallen if you look back just 5 years more.

I am happy to share the raw data upon request. Feel free to contact me for more information.