How a 9-year-old estimated that Americans use 500 million plastic straws a day

Statistics are often vital to public campaigns to fight social problems. The problem of plastic straws is no exception. Here is how 9-year-old Milo Cress developed the oft-cited statistic:

But as Cress began to dig into research on plastics and the environment, he noticed there wasn’t much data: “I couldn’t find anything on our use of straws in the United States,” he said.

So he called straw manufacturers himself, asking what they estimated to be the straw market in the United States per day. Some gave him a yearly estimate, which he divided by 365.

“Others gave an estimate of around 500 million straws,” Cress said. “That was the number that I stuck to, because it seemed to be around the middle of what they were saying.”…

“Why I use this statistic is because it illustrates that we use too many straws,” he said. “I think if it were another number, it still illustrates the fact that there is room for reduction. That’s really my message.”

Sociologist Joel Best, who has written about the social construction of statistics, could have a field day with this.

With all of the debate regarding this figure, couldn’t someone with expertise in this field offer a number that has some more rigor? Even if the number changes a bit, say it goes down to 200 million straws day, it would not matter much as either figure is huge. And this is the whole point (and this is often the case for advocates against a particular social problem): the big number is intended to shock and spur action.

“A Visual History [of race and ethnicity] in the U.S. Census”

Ariel Aberg-Riger argues in a visual history that the United States Census is implicated in matters of race and ethnicity. From the beginning of the piece:

VisualHistoryofUSCensusBeginning

Numbers are never just numbers: they must be conceptualized and then operationalized, they are collected via particular methods, and then given meaning by politicians, scholars, journalists, and the public. Even a simple count is not so easy, particularly when much is on the line for numerous groups.

Adding more context to Americans spending 7% of income on gas

AAA reports on how much Americans spend on gasoline:

Analysts say Americans are now spending 7% of their income on gas, a statistic that is up 1.5% from last year.

If you make $45,000 per year, you’re shelling out over $3,000 just to put gas in your vehicle.

The 7% figure may be interesting in itself but this is a statistic that begs for more background information. Is 7% a lot or a little? Should people be alarmed?

The story already includes two pieces of context:

  1. This is an increase from last year. Generally, people do not want to be paying significantly higher prices year after year. While 1.5% is a low number, drivers would probably not want this number to keep going up.
  2. A slightly lower than average income person or family – the median household income is a bit higher than this – spends over $3,000 on gas. People could read this figure and then think where else that $3,000 could be used.

But, there is more information that could be useful here.

  1. Historically, how much do Americans spend on gasoline? The article includes a one-year trend but how does this look over decades? Are gas prices going up the same way medical costs are going up?
  2. How does this 7% compare to other essential categories of spending such as food (and the groceries vs. eating out breakdown could be interesting) or housing?
  3. What are the total costs of car ownership? Gasoline adds up but vehicle owners also have to factor in maintenance and insurance.
  4. These are average figures for gasoline consumption: how much different will gas costs be for SUV and truck owners (and these are driving the car market) versus small car owners?
  5. How does this compare to gasoline costs in other countries? The rise to 7% may seem like a lot but gasoline costs more in some other industrialized countries and people in other countries drive less than Americans.

While this may be too much to ask for a short news story, gas costs, as well as most other social and economic statistics, are complicated. The numbers do not necessarily interpret themselves. Something going up or down or staying the same is as meaningful as its context and what we make of it.

Earning more yearly from the growing value of your home than a minimum wage job?

Zillow suggests the growth in home values in about half of the United States’ largest cities is higher than working a full-time minimum wage job:

The typical U.S. home appreciated 7.6 percent over the past year, from a median value of $195,400 in February 2017 to $210,200 at the end of February 2018. That $14,800 bump in value translates to a gain in home equity of $7.09 for every hour the typical U.S. homeowner was at the office last year (assuming a standard 40-hour work week),[1] a shade less than the federal minimum wage of $7.25 per hour.

Overall, owners of the median-valued home in 24 of the nation’s 50 largest cities earned more in equity per hour over the past year than their local minimum wage.[2] But homeowners in a handful of U.S. cities made out a lot better than that – in some cases much, much better.

The median U.S. household earned roughly $60,000 in 2017 ($58,978 to be exact),[3] or a little more than $28 per hour. But in six U.S. cities – New York, San Diego, San Jose, San Francisco, Seattle and Oakland – owners of the median-valued local home gained more than that in home equity alone. And if earning a six-figure annual salary represents a certain amount of privilege, homeowners in San Francisco, San Jose and Seattle all made comfortably more than that simply by virtue of owning a local home…

A home is often a person’s biggest financial investment, and according to the 2017 Zillow Group Consumer Housing Trends Report, the typical American homeowner has 40 percent of their wealth tied up in their home. A recent Zillow survey found that 70 percent of Americans[4] view their home as a positive long-term investment.

This is both an interesting and weird comparison. For the interesting part: most people understand the abstract idea of working a minimum wage job. They should know that a full year of work at that rate does not generate much money. The reader is supposed to be surprised that simply owning a home could be a more profitable activity than working.

But, there are a number of weird features of this comparison. Here are four:

First, not all that many Americans work full-time minimum wage jobs. People understand the idea but tend to overestimate how many people work just for minimum wage.

Second, roughly half the cities on this list did not experience such an increase in housing values. Without comparisons over time, it is hard to know whether this information about 24 out of 50 cities is noteworthy or not.

Third, the comparison hints that a homeowner could choose to not work and instead reap the benefits of their home’s value. This question is posed in the first paragraph: “Why work a 9-5 slog, when you can sit back and collect substantial hourly home equity “earnings” instead?” Oddly, after the data is presented, there is a disclaimer section at the end where the difference between working a job and earning money through selling a home is explained.

Fourth, to purchase a home, particularly in the hottest markets cited, someone has to start with a good amount of capital. In other words, the people who would be working full-time minimum wage jobs for a full year are not likely to be the ones who would benefit from the growth in their home’s equity. It takes a certain amount of wealth to even own a home and then even more if someone wanted to profit from just owning homes.

Overall, I would give Zillow some credit for trying to compare the growth in home values to a known entity (a minimum wage job) but the comparison falls apart pretty quickly when one gets past the headline.

The double-edged sword of record home prices in many American metro areas

The housing bubble of the late 2000s may be long gone as housing prices continue to rise:

Prices for single-family homes, which climbed 5.3 percent from a year earlier nationally, reached a peak in 64 percent of metropolitan areas measured, the National Association of Realtors said Tuesday. Of the 177 regions in the group’s survey, 15 percent had double-digit price growth, up from 11 percent in the third quarter.

Home values have grown steadily as the improving job market drives demand for a scarcity of properties on the market. While prices jumped 48 percent since 2011, incomes have climbed only 15 percent, putting purchases out of reach for many would-be buyers.

The consistent price gains “have certainly been great news for homeowners, and especially for those who were at one time in a negative equity situation,” Lawrence Yun, the Realtors group’s chief economist, said in a statement. “However, the shortage of new homes being built over the past decade is really burdening local markets and making homebuying less affordable.”

Having read a number of stories like this, I wonder if there is a better way to distinguish between economic indicators that are good all around versus one like this that may appear good – home values are going up! – but really mask significant issues – the values may be going up because many buyers cannot afford more costly homes. The news story includes this information but I suspect many will just see the headline and assume things are good. Another example that has been in a lot of partisan commentaries in recent years (with supporters of both sides suggesting this when their party was not president): the unemployment rate is down but it does not account for the people who have stopped looking for work.

In the long run, we need (1) better measures that can encompass more dimensions of particular issues, (2) better reporting on economic indicators, and (3) a better understanding among the general populace about what these statistics are and what they mean.

Multiple measures and small trends: American birthrates down, births per woman up

A new Pew report explains this statistical oddity: the annual birthrate in the US is down but women are having more children.

How can fertility be down even as the number of women who are having children is going up? There are complex statistical reasons for this, but the main cause of this confusing discrepancy is the age at which women are having children. Women are having children later in life — the median age for having a first baby is 26 now, up from 23 in 1994 — and this delay causes annual birth rates to go down, even as the cumulative number of babies per woman has risen…

 

Another factor, Livingston said, is the drop in teen birth rates, with black women seeing the biggest drop in that category.

See the Pew report here. An additional part of the explanation is that there are multiple measures at play here. A Pew report from earlier in 2018 explains:

But aside from this debate, the question remains: Is this really a record low? The short answer is: It’s complicated.

That’s because there are different ways to measure fertility. Three of the most commonly used indicators of fertility are the general fertility rate (GFR); completed fertility; and the total fertility rate (TFR). All three reflect fertility behavior in slightly different ways – respectively, in terms of the annual rate at which women are presently having kids; the number of kids they ultimately have; or the hypothetical number they would likely have based on present fertility patterns.

None of these indicators is “right” or “wrong,” but each tells a different story about when fertility bottomed out.

Measurement matters and the different measures can fit different social and political views.

I wonder if part of the issue is also that there is a clear drop in births from the earlier era – roughly 1950 to 1970 which we often associate with Baby Boomers – but the last 3+ decades have been relatively flat. This plateau of recent decades means researchers and commentators may be more prone to jump on small changes in the data. Many people would love to predict the next big significant rise or fall in numbers but a significant change may not be there, particularly when looking at multiple measures.

Reading into a decreasing poverty rate, increasing median household income

Here are a few notable trends in the new data that shows the poverty rate is down in the United States and median household incomes are up:

Regionally, economic growth was uneven.
The median household income in the Midwest grew just 0.9 percent from last year, which is not a statistically significant amount. In the South, by contrast, the median income grew 3.9 percent; in the West, it grew 3.3 percent. “The Midwest is the place where we should have the greatest worry in part because we didn’t see any significant growth,” said Mary Coleman, the senior vice president of Economic Mobility Pathways, a national nonprofit that tries to move people out of poverty. Median household income was also stagnant in rural areas, growing 13 percent, to $45,830. In contrast, it jumped significantly inside cities, by 5.4 percent, to $54,834, showing that cities are continuing to pull away from the rest of the country in terms of economic success…

African Americans and Hispanics experienced significant gains in income, but still trail far behind whites and Asians.
All ethnic groups saw incomes rise between 2015 and 2016, the second such annual increase in a row. The median income of black families jumped 5.7 percent between 2015 and 2016, to $39,490. Hispanic residents also saw a growth incomes, by 4.3 percent, to $47,675. Asians had the highest median household income in 2016, at $81,431. Whites saw a less significant increase than African Americans and Hispanics, of 1.6 percent, but their earning are still far higher, at $61,858.

The poverty rate for black residents also decreased last year, falling to 22 percent, from 24.1 percent the previous year. The poverty rate of Hispanics decreased to 19.4 percent, from 21.4 percent in 2015. In comparison, 8.8 of whites, or 17.3 million people, were in poverty in 2016, which was not a statistically significant change from the previous year, and 10.1 percent of Asians, or 1.9 million people were in poverty, which was also similar to 2015…

Income inequality isn’t disappearing anytime soon.
Despite the improvements in poverty and income across ethnic groups, the American economy is still characterized by significant income inequality; while the poor are finally finding more stable footing following the recession, the rich have been doing well for quite some time now. The average household income of the the top 20 percent of Americans grew $13,749 from a decade ago, while the average household income of the bottom 20 percent of Americans fell $571 over the same time period. The top 20 percent of earners made 51.5 percent of all income in the U.S. last year, while the bottom 20 percent made just 3.5 percent. Around 13 percent of households made more than $150,000 last year; a decade ago, by comparison, 8.5 percent did. While that’s something to cheer, without a solid middle class, it’s not indicative of an economy that is healthy and stable more broadly.

Both of these figures – the poverty rate and median household incomes – are important indicators of American social and economic life. Thus, that both are trending in the right direction is good.

Yet, we also have the impulse these days to (1) dig deeper into the data and (2) also highlight how these trends may not last, particularly in the era of Trump. The trends noted above (and there are others also discussed in the article) can be viewed as troubling as the gains made by some either were not shared by others or do not erase large gaps between groups. Our understandings of these income and poverty figures can change over time as measurements change and perceptions of what is important changes. For example, the median household income going up could suggest that more Americans have more income or we may now care less about absolute incomes and pay more attention to relative incomes (and particularly the gap between those at the top and bottom).

In other words, interpreting data is influenced by a variety of social forces. Numbers do not interpret themselves and our lenses consistently change. Two reasonable people could disagree on whether the latest data is good for America or suggests there are enduring issues that still need to be addressed.