Are Color-Coded Nutrition Labels a Good Idea?

They seem to be, at least for people who normally lack self-control when it comes to food. From a new study led by Joerg Koenigstorfer:

This article investigates whether traffic light color-coded nutrition information helps low- (vs. high-) self-control consumers make more healthful food choices within a given product category. Two in-store lab studies assess the effects of traffic light colors. The colors indicate low (green), medium (amber), and high (red) levels of four negative food nutrients (sugar, fat, saturated fat, and salt). The color-coding was implemented on nutrition labeling schemes shown on the front of actual food packages (pasta meals in Study 1; cereal bars in Study 2). Consumers with low self-control to resist food temptations, but not those with high self-control, make more healthful food choices in response to the color-coded labeling. The behavior is congruent with their long-term goals of controlling their food choices and is evident when traffic light colors vary between both nutrients and products (Study 1) and when traffic light colors vary between nutrients but not products (Study 2). The authors derive theoretical implications and draw conclusions from the perspectives of public policy, retailing, and manufacturers.



Does Daylight Saving Time Affect Voter Turnout?

Another daylight saving time (DST) has come and gone without triggering the collapse of society, but that doesn’t mean it hasn’t had an impact. Research suggests that DST can influence energy use (pdf), the prevalence of workplace accidents (pdf), and the tendency to shirk work responsibilities by looking at random stuff on the internet (a practice known as “cyberloafing.”)

One unexplored aspect of DST is how it might influence voting behavior. Before 2007, the clocks were turned back during the last weekend in October, which means that when November started on a Monday, elections took place only 2 days after the time change (rather than 9 days after.) Since 2007, clocks have been turned back during the first weekend in November, which means that elections now take place 2 days after the time change except when November starts on a Monday (in those cases the election takes place 5 days before DST.)

The question then, is whether voting behavior differs when elections are held two days after the clock change. One theory is that DST decreases voter turnout. The reasoning is that people are more likely to engage in activities when it’s light outside, and turning back the clock decreases evening sunlight. On the other hand, DST also gives people an extra hour to sleep or fulfill other responsibilities. As a result, it may create more free time or raise energy levels on the following Tuesday, and that could increase voter turnout.

So, does DST help or hurt voter turnout?

A new study by Iowa State’s Robert Urbatsch provides an answer. Urbatsch examined three different sets of data with the potential to illuminate differences between post-DST and non-post-DST elections. First, because only certain counties in Indiana observe DST, Urbatsch compared turnout among counties that did and did not have a 25-hour Sunday immediately before an election. Second, Urbatch examined a variety of states and compared turnout in years that election day occurred immediately after DST and years in which it did not. Finally, Urbatch examined voter-level data from the American National Election Study (ANES) survey to see whether individual voting behavior was different when the clocks were turned back two days prior to the election.

All three data sources suggest that turning back the clock for DST increases voter turnout. The Indiana data suggests DST results in a 2.5 percentage point increase in voter turnout, an effect that’s approximately equivalent to increasing the over-65 population by 5 percentage points. Data from individual states suggests that the increase in turnout could be as high as 4.5 percentage points, and data from the ANES suggests DST increases the odds an individual will vote by about 2 percentage points. Furthermore, according to the ANES surveys this effect is almost entirely restricted to people who are not habitual voters.

Given that more turnout generally benefits Democrats, and that non-habitual voters are particularly likely to lean left, the study is reason for Democrats to support the continuation of DST. In fact, 2010 was a rare occasion in which the election did not follow DST, and at the margin that may have contributed to the sweeping Republican victory. (And thus begins the talking point of DST being a liberal conspiracy.)

More broadly, if one extra hour two days before an election can increase turnout, it implies that proposals to extend voting hours or make election day a national holiday could have a large impact on voter turnout. If we want more people to vote, it’s probably a good idea to give them the time to do it.
Urbatsch, R. (2014). Time Regulations as Electoral Policy American Politics Research DOI: 10.1177/1532673X14523034

Crazy Rich Men, Mental Accounting, and Tax Policy

I’ve got two new articles up at Pacific Standard. The first looks at a potential psychological explanation for why rich people keep saying crazy things about the extent to which they’re the victims in our society.

Why do rich men keep revealing themselves to be inept at using the English language to communicate their ideas—however outrageous? Attempts to explain their zealous defenses of the one-percent generally involve phrases like “limited view of reality” or “social bubble,” but perhaps the most interesting explanation comes from psychological research on the theory of needs-based reconciliation…

The theory posits that perpetrators and victims each desires a different basic psychological need—perpetrators want social acceptance, victims to feel empowered—and reconciliation will be most likely when each is fulfilled…

It’s not a stretch to map these findings onto the American social system…

Read the whole thing!

The second article takes a look at new research on mental accounting, and specifically how it might be relevant to tax policy.

The imagined origin of the money influenced how participants chose to spend it. As predicted, participants were less likely to spend the inheritance money on either purchase. Participants who did choose to spend the inheritance money were less likely to spend it on the resort compared to money from the other accounts…

Even if individuals draw some emotional benefit by saving inheritance money, from a social standpoint it’s better if people—and wealthy people in particular—spend their money on durable goods or semi-risky investments…

It seems that the tendency to save inheritance money is another reason to support a higher estate tax. If mental accounting is preventing inheritance money from being spent in the most efficient way, that strengthens the case for raising estate tax revenues to fund welfare programs (and if you lean right and cringe at that word choice, just replace “welfare programs” with “other tax breaks for the wealthy that are more stimulative.”)

Once again, read the whole thing!

Sorry Talking Heads, You Know Nothing About What Matters in the NFL Playoffs

For years, sports commentators who spew evidence-free clichés about the keys to athletic victory have monopolized our airwaves. But recently a technique some of them view as akin to witchcraft, but that’s more commonly known as “statistical analysis,” has begun to bring an end to their reign of terror.

The latest volley in this ongoing battle comes from a new study by Joshua Pitts of Kennesaw State University. Pitts analyzed all 445 NFL playoff games from 1966 through 2012. Among the factors he examined were the number of previous playoff games and playoff wins of quarterbacks and head coaches, the playoff experience of all players relative to their opponents, statistical measures of offensive and defensive quality in terms of both regular season passing and rushing, whether a team was playing at home, and the degree to which a team entered a playoff game on a winning streak. The outcomes Pitts examined included whether a team won their playoff game, and their points scored, points allowed, and margin of victory or defeat.

The most noteworthy of Pitts’ findings is that there’s little evidence playoff experience matters.

Perhaps a surprising result is that neither the previous playoff experience of a quarterback/head coach nor the number of previous playoff wins for a quarterback/head coach has a significant impact on any of the measured outcomes in this study after holding current team quality constant.


All the various measures of previous playoff experience included in this study, including measures of quarterback, head coach, and team playoff experience, are rarely statistically significant determinants of the outcomes measured in this study. Furthermore, even when these measures do prove statistically significant, the magnitude of the impact on the dependent variables tends to be extremely small.

So much for that talking point. At least there’s always the “Playoff success starts with running the football and stopping the run” cliché. Oh wait…

The relative productivity of a team’s passing offense and defense in the regular season is consistently a statistically significant determinant of all of the outcomes measured in this study. However, the relative productivity of a team’s rushing defense is not a statistically significant determinant of any of the measured outcomes. Furthermore, the relative productivity of a team’s rushing offense is only statistically significant at the 10% level in a single specification presented in column 8 of Table 4. This provides overwhelming evidence, as suggested by Arkes (2011), that the key to victory in the NFL postseason is controlling the passing game.

Pitts also found almost no evidence that being on a winning streak (“They’re peaking at the right time!”) had an impact on the outcome of playoff games.

But the news for institutional clichés wasn’t all bad. It turns out the defense does make you marginally more likely to win a championship.

For every 1.4% increase in relative offensive productivity, a team is about 1% more likely to win a postseason game. Similarly, for every 1.1% increase in relative defensive productivity, a team is about 1% more likely to win in the postseason. In general, the marginal effect of defensive productivity is a little larger than the marginal effect of offensive productivity which provides slight support in favor of proponents of ‘‘defense wins championships.’’

Another noteworthy finding concerned home field advantage:

The home team is about 18–29% more likely to win, depending on the specification of the model and holding other factors constant. The results shown in Table 4 predict a 6–10 point advantage for the home team in a matchup between two identical opponents, essentially implying that home-field advantage is worth at least a touchdown in the postseason.

Bookies generally give a team about three points for home field advantage, so this implies that in the playoffs people may be underestimating that edge.

The fact that the way pro football is played can change in just a few years means these results should be taken with a grain of salt. Perhaps there’s been something important in the last five or ten years but it’s been masked by the prior 30 years of data. Alternatively, it’s possible that some of things that do appear to make a difference have already ceased to matter or will cease to matter in the next few years. But overall the study provides some compelling evidence that the clichés you hear about winning in the postseason are often disconnected from reality.

Finally, because no NFL playoff post is complete without a discussion of Tim Tebow, Pitts also used his models to predict the greatest playoff upsets of all time. And wouldn’t you know it, the Broncos Tebow-led overtime win against the Steelers in 2011 ranked in the top 10 in Pitts’ model based on expected win percentage and his model based on expected points margin. (The Vikings 1987 Divisional round win over the 49ers and the Patriots win over the Rams in the 2001 Super Bowl were ranked first, respectively.) In other words, to the surprise of nobody, Tebow’s playoff victory was a statistical anomaly (i.e. fluke.)
Pitts, J. (2014). Determinants of Success in the National Football League’s Postseason: How Important Is Previous Playoff Experience? Journal of Sports Economics DOI: 10.1177/1527002514525409

The Impenetrable Bulwark of Vaccination Lies

America has a problem. Some people are spouting the lie that vaccines can cause autism and other people are believing them.

This has led to some unfortunate false-equivalence when the issue is discussed, and wouldn’t you know it, that false equivalence makes people less likely to believe the truth. Sometimes there’s no false equivalence; people who lie about vaccines are just handed a platform to broadcast their destructive beliefs.

Once people believe vaccines can cause autism, those beliefs may be very hard to change. For example, research (pdf) by Dartmouth’s Brendan Nyhan and the University of Exeter’s Jason Reifler has shown that information aimed at correcting false beliefs is often useless. They found that not only does corrective information fail to make people believe the truth on issues ranging from the war in Iraq to tax policy, but if the new information runs counter to an ideological belief there can be a “backfire effect” wherein people strengthen their incorrect belief.

So what about specific attempts to correct misperceptions about vaccines? A new study by Nyhan, Reifler, Sean Richey of Georgia State, and Gary Freed of the University Michigan paints a bleak picture.

In the study, which is set to be published in Pediatrics, 1759 parents with a child under the age of 18 were surveyed about their attitudes on vaccines. A few weeks later they were surveyed again, but this time participants were divided into a control group and four different treatment conditions.

Each treatment condition was aimed at improving perceptions of the risks and benefits of the measles-mumps-rubella (MMR) vaccine: There was 1) an “autism correction” condition, in which participants were presented with a CDC explanation debunking the link between vaccines an autism, 2) a “disease risk” condition, in which participants were told about the adverse consequences of having MMR, 3) a “disease narrative” condition, in which participants where presented with a mother’s account of her child’s hospitalization for measles, and 4) a “disease images” condition, in which participants were presented with pictures of a child who had one of the diseases. Participants in the control group were presented with additional information about bird feeding. After receiving one of the five types of additional information parents reported their attitudes about vaccine side effects and the likelihood that they would vaccinate a future child.

What Nyhan and his collaborators discovered is mostly bad news. While parents in the autism correction condition were less likely to agree with the statement “some vaccines cause autism in healthy children,” they did not have fewer concerns about MMR side effects and they were not more likely to vaccinate their child. In fact, parents in the autism correction condition with less-favorable attitudes toward vaccines (attitudes in the lower third of the sample) were less likely than other participants to say they would vaccinate their child in the future.

As for the other conditions, none of them increased the likelihood of vaccination either. The “disease narrative” condition even appeared to make parents more likely to believe that the MMR vaccine could have serious side effects.

The lesson is that, at best, throwing together an information-based plan to increase vaccinations probably won’t work, and at worst, it will be counterproductive. We tend to think about the necessity and risk-free nature of vaccinations as facts – that telling somebody vaccinations don’t cause autism is like telling them that the body needs oxygen. But evidence is building that attitudes about vaccinations may be more like an ideological belief. For some people, hearing that vaccines don’t cause autism is like hearing that tax cuts for the wealthy aren’t good for the economy. They’re probably not going to be convinced to change their mind in an afternoon.

The question then, is where do we go from here? At this point it feels like the only good answer is “the drawing board.”

Addendum: For a good example of the harmful false-equivalence described above take a look at NBC’s coverage of the study. Despite the fact that the study has nothing to do with the actual efficacy or side effects of vaccinations, the article quotes two anti-vaccine activists as saying that the study somehow vindicates their position, and it does this before quoting a single medical expert.

Here’s the most aggravating section:

“It is a big mistake for public health officials to assume that those resisting public health messaging about vaccines and diseases are ignorant, uneducated, ‘anti-science’ and that they lack social conscience,” said Barbara Loe Fisher, president of the National Vaccine Information Center and a frequent critic of vaccines.

Michael Belkin, 60, a Seattle vaccine critic whose infant daughter died in 1998 after recommended shots, said parents want to make up their own minds.

“People are skeptical about drug companies. Why should they not be skeptical about vaccines?” he said.

Actually, if you define “ignorant” and “uneducated” as “not believing true things are true,” those resisting public health messaging about vaccines are ignorant and uneducated. The fact that it’s hard to make these people change their minds does nothing to vindicate their position.

There’s been enough of a focus on false-equivalence in the media that you would think NBC would be more careful about it, especially when dealing with an issue like vaccination, where false-equivalence is much more harmful than in political domains. It’s truly a shame that NBC chose to re-litigate a faux-debate in a story about a study that doesn’t even profess to shed light on the facts relevant to the debate.
Nyhan, B., Reifler, J., Richey, S., & Freed, G.L. (2014). Effective Messages in Vaccine Promotion: A Randomized Trial Pediatrics

Babies Can’t Read

Evidence that a growing segment of baby products may be made by hucksters:

Targeted to children as young as 3 months old, there is a growing number of baby media products that claim to teach babies to read. This randomized controlled trial was designed to examine this claim by investigating the effects of a best-selling baby media product on reading development. One hundred and seventeen infants, ages 9 to 18 months, were randomly assigned to treatment and control groups. Children in the treatment condition received the baby media product, which included DVDs, word and picture flashcards, and word books to be used daily over a 7-month period; children in the control condition, business as usual. Examining a 4-phase developmental model of reading, we examined both precursor skills (such as letter name, letter sound knowledge, print awareness, and decoding) and conventional reading (vocabulary and comprehension) using a series of eye-tracking tasks and standardized measures. Results indicated that babies did not learn to read using baby media, despite some parents displaying great confidence in the program’s effectiveness.

And speaking of products with false claims, USC Morgan Polikoff is beginning to unleash his research on the meaningless practice of calling a textbook “Common Core Aligned.”

Publishers are marketing all kinds of new textbooks they say align with the Common Core standards.

In reality, “they do not look that different from the previous versions,” said Morgan Polikoff, an associate professor at the Rossier School of Education at the University of Southern California.

In a study debuted last weekend at an Education Writers Association conference in Los Angeles, Polikoff analyzed three “Common-Core aligned” fourth-grade math textbooks adopted in Florida and one commonly used textbook that is not aligned to any particular standards.

He found that 15 to 20 percent of textbooks cover topics outside the Common Core standards, while 10 to 15 percent of the standards are not reflected in the texts.

In the long run, this probably isn’t a big deal, but over the next few years it’s going to be a big pain to get this right.