The Harry Potter Effect
I’m a big Harry Potter fan. Despite my plan to purchase Harry Potter and The Deathly Hallows after waking up on Saturday morning, I could not resist temptation and found myself in line at Kroger at 11:55pm on Friday night. Coincidentally, I had purchased Harry Potter and The Order of the Phoenix at this same store four years ago, and there were only about five people in line then. On Friday, there were about 50 people there. I’d hate to have been at the nearby Barnes & Noble.
Anyway, when I wasn’t sleeping or playing with the kids on Saturday, I read the book. I finished it about 24 hours after making the purchase (I loved it!). I did not even think about turning on the Braves game, which is rare for me. I don’t think I’ve missed a televised Saturday game in a long time. Given the popularity of the book, I wondered how many others did the same and if this had an effect on alternative forms of entertainment, like baseball games.
The league averaged 39,110 fans at the ballpark on Saturday. Last season, these same home teams averaged 38,003 for Saturday games in July. That’s an increase of 2.9 percent over the 2006 season. Attendance is up this year; but, because of scheduling differences and other problems, isolating how much attendance is up is difficult. Looking at the 2006 and 2007 seasons through July 22, game attendance is up about 4 percent—1.1 percentage points more than this past Saturday’s increase. Assuming that the league’s attendance would have been four percent higher than it was in July 2006, Harry Potter cost teams an average of 418 fans per game—a total of 6,270 fans. Using average ticket prices this translates to about $138,000 in lost gate revenue. Add in concessions and the losses are still small. The biggest impact probably occurred with in television watching—these are the marginal baseball watchers most likely to skip a game for book—but I suspect the effect there was not all that large either.
In any event, these numbers are rough (jagged is more like it) and just for fun. Speaking of fun, I feel like I need to read the book again. 
J.C. Bradbury is an economist and associate professor at Kennesaw State University in metropolitan Atlanta. He is the author of The Baseball Economist and has operated Sabernomics.com since March 2004.
July 23rd, 2007 at 2:46 pm
I’m a Phillies fan. I also enjoy the Harry Potter books. The Phillies played the Padres in San Diego on Friday night; the game started at 10:05 ET, and as you know the book came out at midnight ET.
My evening went as follows:
10:05: turn on Phillies on radio. (I have various reasons for disliking my cable company enough to not spring for the package that would allow me to get weekday Phillies games on TV.)
11:25 or so (fourth inning?): like you, decide that I really want the Harry Potter book tonight (I had been planning to buy it Saturday during the day), and therefore start walking to the bookstore, which is a twenty-minute walk away.
11:45: get to bookstore. Wait in line for a long time. Frequently send text messages to GOOGL to get updates on the score of the game. (If I had a portable radio of some sort I might have brought it, but I don’t.)
12:50: get book.
1:10: get home. If I remember correctly, the ninth inning had just started; the score was 7-3 in the Phils’ favor, but with their bullpen I can’t just turn the game off and be assured that they’ll win. So I listened to the ninth inning and only then did I pick up the book.
So in the end I listened to about half the game on the radio, instead of the whole game as I probably would have without the book being released.
(Also, the people who are most likely to not go to a baseball game because of the book are also the ones who are most likely to have bought the book at midnight… and if they’re fast readers, they would have finished it before a Saturday night game. I did.)
July 23rd, 2007 at 4:22 pm
You might also want to consider the sunk cost effect on baseball game attendance. In general I’d think that the cost of a ticket is about the cost of the new Harry Potter book. However, in many cases the purchase of the book is POS where as the baseball tickets are bought in advance. Therefore, the swing of choice would be toward the time dependent action (act now, the game is only played once). Further reasoning would point out that the book is not actually time dependent in the long run. While it is only released at one point in time, the book is a physical object that can produce benefit well after Saturday while the ticket can not.
If you want to look at a similar situation, I’d advise comparing apples to apples. Perhaps a blockbuster movie would be better. In that instance the product is time dependent and must be consumed at that specific moment. Just a thought.
July 23rd, 2007 at 5:16 pm
At the risk of overgeneralizing, I’d guess that lots of guys were encouraged to take a guys’ day/night out last Saturday. That often includes a ballgame.
July 24th, 2007 at 7:12 am
Torchy,
Just having a bit of fun here. Plus, for a true Potter fan, TDH could not be put off. I basically refused to watch the news for a week for fear of accidentally reading spoilers.
Doug,
So you’re saying there were a few more beers and spicy turkey melts consumed on Saturday?
July 24th, 2007 at 11:34 am
I pre-ordered from Amazon and UPS delivered it late Saturday morning. I finished it last night about 30 minutes before the Braves game. I guess the West Coast trip helped give me time to read.