Friday, July 22, 2016

Athens Traffic Volume Data

So I'm playing with traffic data for Athens-Clarke County. Here's a map I made of key data points, and an embed of the map (hopefully) below. The data points are just of key spots, not all of them available in the data. Click on a spot to see whether there was an increase from 2008 to 2014 in traffic for that location. Some are on campus, which is kinda useful, and I plucked out a few around town.

I actually have every year, 2008 to 2014, for 30 spots in ACC, all in a nice Excel file, but I can't easily stick that in this blog and, after all, no one probably cares. If you really want it, I can email it to ya. Eventually I'll enter them all. No real automatic way to do it. Well, there may be, but I'm not gonna figure it out today.

The biggest increase is 82.3 percent on Epps Bridge Road (near Old Epps Bridge Road), no doubt driven by all the commercial activity out that way, just over the Oconee County line. In 2008 the daily volume was 2,414 vehicles, in 2014 the volume was 4,396. Not coincidentally, there's been a 15 percent decrease on Atlanta Highway near Jennings Mill Road.The biggest decrease is on Baldwin Street on the UGA campus, a 23.9 percent drop.


Trump's Speech

As the entire world knows, Donald Trump delivered a long acceptance speech last night -- 75 minutes, the longest in decades. He used "I" 66 times, according to the official text. That may seem a lot, but he softened it with 62 uses of "we." He said "I am" 13 times (never using "Sam" before it) and said "I will" 14 times.

The official text doesn't list a single "believe me" but he added them as he went. It's among his favorite phrases. That's the salesman in him bubbling out.

Above is a word cloud of his speech, which ignores "I" and similar pronouns and small words. In that case, the winners are forms of America, country, and the usual stuff you see in political speeches. "Immigration" shows up nine times, "Muslim" only once (as "Muslim brotherhood" in Egypt as a criticism of Hillary Clinton).

Oh, yeah, "Clinton" is uttered only 11 times out of 4,634 words, as was "Hillary" (either alone or in combination). But "will" gets said 89 times, perhaps the most of any single word, best I can tell. There's probably a rhetorical paper in the use of "will."

According to one site, the reading level of the speech was grade 8.3 with 15.3 words per sentence. The longest sentence boasted 56 words. To the left are the stats, and for the Flesch-Kincaid Reading Ease of 62.5 that is "plain English" that is "easily understood by 13- to 15-year-old students."

And yes, I hope to repeat this analysis of Clinton's acceptance speech next week.

Wednesday, July 20, 2016

Trucks in Georgia

The least populated Georgia counties tend to have the greatest percentage of pickup trucks compared to other registered vehicles.

Can I have a duh from the audience?

I know, it seems obvious, but in playing with some other data I came across the percentage of all motor vehicles in each Georgia county that happen to be trucks. For you statistical nerds out there, the correlation between population and percentage of vehicles that are trucks is -.72. That's a strong negative correlation, meaning of course the greater the number of folks who live in a county, the fewer pickups (which are found, obviously, in more rural counties with fewer folks who live there).

The table below ranks counties by percentage of trucks among all vehicles and includes the rank in population (out of 159 counties). As you can see, the Trucking Top 10 is an imperfect mirror image of the Population Top 10.



I could have flipped this. The #1 population county, Fulton, is #159 (last) in proportion of trucks among all registered vehicles. Indeed the four most populous counties are last when it comes to trucks.

Locally, Clarke County (Athens) is #19 in population but #153 in trucks (17.6 per 100 vehicles). Oconee is #52 in population, #132 in trucks (22.7 per 100 vehicles).

Just so you know, 35.2 percent of all vehicles in Echols are trucks, this in a county with 4,057 or so souls.

Two or More Races

Here's an odd one for you. See the graphic and below we'll explore that sudden drop. The data is based on the number of students at UGA (undergrad and grad) who listed themselves as "two or more races" from Fall 2000 to Fall 2015 (the last data available).

We see the steady increase from 2000 to 2007-8 and then a sudden, stunning drop in 2009. Here are some possible explanations:

    • The Great Recession decreased all students in Fall 2009. Except this isn't the case. There were 34,180 students in Fall 2008, 34,885 in Fall 2009. So it's not a function of the number of students decreasing.
    • Students who listed two races were hit hardest by the recession and fewer attended UGA that year. Possible. I have no data either way, but it's a plausible hypothesis that needs testing.
    • More listed themselves in other racial categories that year. Except this isn't the case either. There's an increase of 185 in the "Black of African American" category from '08 to '09, so this may explain some, but not all, of it.
    • The questionnaire or admissions instrument changed. I don't have access to this, but what's truly odd is the steady, dramatic increase from a low in 2009 to 2015. My gut says something changed in how students click a box, but I have no evidence of this one way or the other.
    • One unimportant change between '08 and '09 is the addition of a category for "Hawaiian or other Pacific Islander." That played no role with only five listed in '09.

These are the statistical quirks that deserve a much closer look, if I was so motivated. There's no news story here, but there probably was one back in 2009.

Friday, July 15, 2016

Not So Unusual a Question

Every election cycle a handful of journalists discover that asking survey respondents to predict who is going to win the election can be far more interesting, and accurate, than the usual asking of who they support and adding up the results. A HuffPo piece posted online Thursday afternoon is the latest. It includes this breathless headline and subhead:
Unusual Polling Question Reveals Which Candidate
Is More Likely To Win In November 

We usually ask voters which candidate they plan to cast a ballot for.
But asking which one they think will win actually reveals more.
Asking survey respondents to predict who is going to win, that's "unusual?"

Not really.

The ANES has been asking this question in every presidential election year since -- wait for it -- 1952. Go to the ANES core question list and search for "Who does R think will be elected president in November" and you'll see it listed for all those years. I've analyzed this question extensively for decades, so I kinda know this question, its accuracy, and even its theoretical strengths and weaknesses.

A note to the HuffPo author and everyone ... yes, this question is accurate, but not always so. Recent example, Brexit. More U.K. folks predicted Remain would win than Leave, and we all know how that turned out (my breakdown of that question here). The article does a nice job linking to several of the "Who's gonna win?" questions so far this election cycle, and notes that Hillary Clinton scores significantly higher than Donald Trump. One recent question, for example, has it Clinton 54-26 over Trump in prediction.

But these are national surveys. I'm not saying they're wrong, I'm saying it's too early to pay any attention to the "Who's gonna win?" question, plus as we all know the U.S. presidential election is by state, not nationally, though we can take a lot of guidance from national polls. As an aside, ANES also often -- but not always -- asks for a prediction of a respondent's state as well.

That caveat aside, let's look at some data. First off, people tend to believe their own candidate will win. Three-fourths of Mitt Romney supporters believed he would win in 2012. See the graphic below. As you can tell, if you add predictions of victory by the eventual winners and eventual losers, the result ranges in the 70s or 80s, percent-wise. Indeed, it's gone up in the last few elections, which in itself is kinda interesting.

So how accurate is the "Who's gonna win?" question? Very. The last time it was off was the hotly contested 2000 election and in some ways it was right in that Al Gore did indeed win the popular vote, just not the Electoral College. In general, as research shows, the question is accurate, though the percentages are often higher on prediction question for the winner than they are for the traditional counting up of preferences. For example, two polls in November 2012 had Barack Obama over Romney with 57 and 55 percent of the vote, respectively. Obama won with 51.1 percent of the popular vote. So there is a bit of inflation here. It's better at predicting a winner than the degree to which a candidate will win.

Thursday, July 14, 2016

It's Pettit, Dammit

We've lived in our Athens, Georgia, neighborhood for 25 years, and for 25 years we've driven down Pettit Lane to get to our street -- Greenbrier Way.

And as much as I love Google Maps, they've always had it wrong. The black circle on the Google Map below is our house, but note the spelling of the cross street. Pettits.

But if you go to the "street view" you see this below. Even Google can't agree with itself. I've reported this a few times over the years, but I dunno that anyone at Google actually reads the reports.

Tuesday, July 12, 2016

Of SLOPs, Bad Polls, and Football

So there's this above, the most popular college football team in every state. Notice anything, Bulldog fans? Georgia Tech is the most popular in Georgia. Want even more? UAB is the most popular team in Alabama.

You're thinking, WTF?

Here's an explanation, from the story linked above in the first graf:
Fans voted through Google Forms, casting their vote for one of the state's teams. For example, 459 readers voted in the state of Alabama poll, with 249 picking UAB as their "favorite" team and 110 voting Alabama as their "favorite" team. Auburn received 71 votes and 29 people picked Other, a group that could include South Alabama or FCS team Jacksonville State.
This is a SLOP, a self-selected opinion poll, also known in the public opinion business as complete bullshit. Fun, yes. Interesting, maybe. But never ever to be taken seriously. Given this is about football, it's okay as nothing from this poll really matters except, maybe, hurting the feelings of certain fans. Maybe Georgia Tech fans know how to use Google Forms and UGA fans don't. Maybe a bunch of UAB fans organized and swamped the poll to knock out the Tide and War Eagle/Tiger/Plainsmen. Who knows, and it really doesn't matter of course.

You can see the stats here, via the Reddit page.