I’m happy to announce that Elizabeth Simpson won the Dad-or-Daughter Songwriting Contest by correctly identifying Friend Zone as the song that I coauthored with my daughter, as well as correctly identifying a line in that song that I composed (“But you just laughed it off and said we’d always be bros”) and a line in the song that Anna composed (“I bought a shirt today with your favorite band.”).
Elizabeth turns out to be a former student from my 2006 small group in contracts. In her email, she describes the method behind her entry:

I listened to some of your daughter’s other songs to get a sense of her songwriting voice. Then, I picked the song that diverged most from her signature style. Finally, to get inside your head, I tried to channel my own father (a white, male, lawyer, economist who loves making wagers about his weight or any other subject). He is prone to composing spontaneous poems, so I pretended that I was trying to pick out a rhyme that he would be apt to come up with.

A Ph.D student from Berkeley, Zachary Liscow, came closest to predicting the total number of views, which was over 3,200. A grateful father thanks you.
For the number crunchers out there, a quick and dirty analysis of the 29 Freakonomics votes mildly rejects the wisdom of the crowds. The proportion of people choosing Friend Zone in the first half of entries was 57.14 percent, while the proportion choosing Friend Zone in the second half of entries was 46.67 percent. So, later entrants didn’t seem to benefit from the public prior information.
Listeners liked Friend Zone the least of the three songs. (Longer seemed to be the favorite.)
The story behind the writing of the song is an example of creativity prompted by resistance. I originally had challenged Anna to write a song using a kind of blues chord progression. She resisted. I then went further and came up with the basic idea of a protagonist who was trying to get out of the “friend zone.” Anna still resisted. And I even came up with a melody for the tune and the basic hook. Anna was still not feeling it but came forward with a first draft of the remaining lyrics. I wasn’t satisfied and substituted many of my lines into the song and added the final verse. Friend Zone is also the only song of Anna’s on which I play guitar. That’s me laying down the funky lead riff during the break.
Honorable mention goes to Caleb B who wrote:

Since my incentive is to have the maximum amount of leisure time for myself, and not listen to amateur music, I have chosen to not listen to any of the songs, but simply guess using a combination of publicly available guesses below.

My favorite comment (in part because of the gory detail of its method) was one of the last contest entries. Karearea wrote:

Unless Anna has a special talent for mimicking the writing style of 52-year old men, the song written by Ian really has to be Friend Zone. That was my initial feeling about it anyway. However I decided to seek professional consultation, starting with my 22-year old daughter and her boyfriend. To my shock and horror they thought it was Your Way, leading me to consider that they might be candidates for some sort of “re-education.” I then consulted my 14-year old son – he instantly identified Friend Zone as having the try-hard feel of a 52-year old man attempting to write like a 14-year old girl. I then sought the opinions of my 6-year old son and his friend but they were not up to the job – their stories changed under repeated questioning and after a lengthy appeals process involving claims of parental intimidation and bribery their testimony was determined to be inadmissible. In desperation I asked my husband (59-years old). Usually his choices are useful in that the wrong answer is immediately identified, but he chose Friend Zone too, leading to a long period of self-doubt, soul-searching and reflection on my part. Next on the list was my 18-year-old daughter who chose Friend Zone. By the time she got to the line “We could hug it out in a whole new way” she was apparently in no doubt that this was a tragic case of an old man trying to get down with the kids. Then I moved on to my 12-year-old daughter (also a writer of lyrics). She wasn’t sure but felt that Friend Zone may well have been written by “a dork Dad trying to be cool, sort of like if our Dad tried to write something like that”. She was concerned though that father and daughter may have both engaged in deliberate deceit in their writing styles. Finally, I decided to disregard all opinions except my own and those who agreed with me.

Anna was particularly amused by the “hug it out” analysis. Friend Zone is not one of Anna’s favorite songs. In performing it, she gave the old college try. But I think you can tell she was not that into it when she abashedly sings “make sweet romance.”
I hereby officially announce my retirement from the songwriting game. But you can check out more of Anna’s music at her YouTube channel.