February 25, 2024

Archives for April 2004

Voting Machine Inspection

Yesterday, I had a chance, with some colleagues, to look over the new e-voting machines that will be used in the future here in Mercer County, New Jersey. They’re AVC Advantage machines, made by Sequoia. The machines were available for public inspection at Princeton Borough Hall. (They’re available today too, at the Suzanne Patterson Center, right behind Borough Hall.)

The machines have a low-tech user interface, a big board covered with a paper printout of the ballot, with switches underneath the paper. The paper is covered by a thin sheet of clear, flexible plastic. You press on the little box printed next to your candidate’s name, and a switch under the paper is triggered. A computer inside the machine detects the switch-press and lights a little green X next to the candidate’s name. When you’re done, you press a bright red “Cast Vote” button, which is supposed to cause the computer to record your vote.

The machine’s minders were careful not to let us look at the mechanism inside. When we got there the access panel was ajar; but when I asked whether I could look inside one of the minders quickly closed and locked it.

The physical security of the machine looked pretty lousy. The guts of the machine are behind a large plastic door on the back side of the machine. The door bent unexpectedly when I tugged gently on its corner. It seemed to be made out of an ordinary plastic, not the thick, tough kind used in kids’ toys these days. My guess is that I could probably rip off the door with my bare hands. It could certainly be removed with a screwdriver or crowbar. The lock looked wimpy too, like the kind of lock you might put on a toolshed or a locker at the gym; not as good as a standard house or office key. I doubt anyone could get the panel open during an election without being noticed, but that owes more to the number of people around than to the inherent strength of the door and lock. The machine will be physically vulnerable beforehand when it’s not as well attended.

They had a copy of the instruction manual that is normally given to poll workers, but they seemed nervous when we looked at it. It seemed to me that they were trying to decide whether to take the manual away from us. The manual had a small black-and-white photo of the machine’s innards, showing a circuit-board of some sort, and a printer.

The vendor offers little if any technical information about the machine. They do publish a brochure, which helpfully observes that use of these machines offers “[n]othing less than the complete elimination of human error.”

A Grand Unified Theory of Filesharing

Recently we’ve seen several studies of the impact of filesharing on CD sales. We have enough data now to draw some (very) preliminary conclusions, assuming the studies are correct. Despite the apparent contradictions between the various studies, I think there is a plausible theory that can explain them all – a Grand Unified Theory of Filesharing.

First, let’s review the three main results that have to be explained.

  • Survey-based studies, which ask people whether they use the Internet, whether (and how much) they use filesharing, and how many CDs they buy, find that people who fileshare buy fewer CDs.
  • The recent econometric study by Oberholzer and Strumpf, based on per-album time-series data on filesharing activity, CD sales, and other factors, found that filesharing has little or no effect on CD sales.
  • Eric Boorstin’s study found, controlling for differences in personal income, that there is a strong positive correlation between Internet usage and CD purchasing. This held true for all age groups, except the 15-24 group, for whom Internet usage correlates negatively with CD purchasing.

(It’s undisputed that CD sales have dropped sharply in recent years, but there are several plausible causes for that drop. That’s a topic for another day. Here, I’ll assume only that filesharing is not the only cause of the sales drop, so that we don’t need filesharing to explain the drop.)

The Grand Unified Theory explains the study results by breaking down the users of filesharing into two subpopulations, which I will call Free-riders and Samplers.

Free-riders are generally young. They have few if any moral qualms about filesharing, and they tend to assume that others feel the same way. They use filesharing to accumulate libraries of music, as an alternative to buying CDs.

Samplers are generally older and more risk-averse. They are highly engaged with cultural products of all sorts. They are morally conflicted about filesharing, and use it mostly to download songs that either aren’t for sale, or that they don’t value enough to pay for. They buy music that they really like, and filesharing causes them to find more music they like, so it tends to increase their CD purchases.

Now let’s look at how the theory explains the studies’ results.

In survey-based studies, Free-riders admit to filesharing and to buying fewer CDs because of their filesharing. But Samplers are reluctant to confess their filesharing to a stranger, being more risk-averse and more attuned to the dubious moral status of filesharing (not to mention its illegality). The result is that Free-riders are overcounted in survey-based studies, and Samplers are undercounted, so survey-based studies find that filesharing depresses CD sales.

The Oberholzer and Strumpf study measured the actual impact of both Free-riders and Samplers, and found that the lost sales caused by Free-riders are balanced by the increased sales due to Samplers.

The Boorstin study had different results for different age groups. His 15-24 age group was mostly Free-riders, who buy fewer CDs when they have Internet access, because their filesharing substitutes for purchases. His older age groups were mostly Samplers, who buy more CDs because of filesharing, and who are also, because of their high level of cultural engagement, predisposed to both Internet usage and CD purchasing. Therefore he found that young Internet users buy fewer CDs, while older Internet users buy a lot more.

So there you have it: a theory that explains the study results, and that seems plausible (to me, at least). Of course, there are lots of caveats here. One or more of the studies might be wrong; or the studies might be right but the theory wrong. But bear with me for a bit longer as I explore the possible consequences of the theory.

The theory says that the net effect of filesharing on CD sales is roughly zero, because of a balance between the negative impact of the Free-riders and the positive impact of the Samplers. But what happens in the future? It all depends on what happens to today’s Free-riders.

Perhaps today’s Free-riders will mature into Samplers, to be replaced by a new generation of Free-riders, so that the effects of the two groups continue in a rough balance. Or perhaps today’s Free-riders, never having known anything else, will keep Free-riding as they get older, and the balance will tip toward Free-riders.

It’s also worth noting that the theory does not predict whether (illegal, free) filesharing will reduce online sales of music. Probably the answer depends on what the online alternatives look like, and how convenient they are to use.

So the theory can explain the present situation, but it doesn’t make strong predictions about the future; or, if you prefer, the theory comes in several flavors, which differ in their future predictions. If we had a better handle on what makes one person a Free-rider and another a Sampler, we could make better predictions.

[Thanks to Eric Boorstin and Andrew Appel for helping me develop and refine these ideas.]

New Study of the Net

Eric Boorstin, a senior at Princeton, just filed his senior thesis, Music Sales in the Age of File Sharing. The thesis includes a clever study of the impact of Internet usage on CD sales. This is a twist on previous studies, which have tried to correlate CD sales to usage of filesharing. The tradeoff here is that although Internet usage is one step removed from filesharing, the data on Internet usage are much more detailed and much more reliable than the data on filesharing usage.

Eric worked from two datasets. The first dataset came from SoundScan, and gave him aggregate sales of CDs, on a week-by-week basis, for many separate metropolitan areas in the U.S. The second dataset came from the U.S. Census Bureau, and contained data on population, income, and Internet usage, broken down by age group and geographic area. The census data came from 1998, 2000, and 2001. Combining these datasets, he ended up with data for CD sales, age group demographics, income, and Internet adoption, at three different points in time, in ninety-nine separate metropolitan areas in the U.S.

Eric took these datasets and did a regression to determine the correlation between Internet adoption rate and CD sales, broken down by age group. He controlled for differences in personal income. (For more methodological details, see the thesis.)

For people in the 15-24 age group, he found a significant negative correlation between Internet adoption and CD sales. For people in all of the age groups older than 25, he found the opposite

Princeton Proposes Quotas to Control Grade Inflation

Princeton is considering putting a cap on the number of A’s that professors could award to students, as a way of fighting grade inflation. Details are in Alyson Zureick’s story in today’s Daily Princetonian. To my knowledge, Princeton would be the first major university to take such a step. The proposal would have to be approved by a vote of the faculty before taking effect.

Grade inflation is a real problem, and it’s a hard one to fight. There are weak but steady pressures that push grades up over time. A professor, faced with a student on the borderline between two grades, finds it easier to give the higher grade; and at the end of a long semester of hard work by professor and student, it feels right to give that borderline student a tiny nudge upward. Students complain about low grades, and sometimes they can point to a grading error that justifies an upward adjustment; but rarely if ever do they complain about generous grades. These nudges and corrections slowly push the average grade upward.

I also think, notwithstanding the occasional grumbling of old-timers, that our students have gotten more capable over the years. If this is true, then grades naturally inflate, unless we grade the same work more harshly than we did in the past.

In recent years, Princeton’s strategy has been to report comparative statistics, telling each department how its grade distribution compares to others, and telling each professor how his grade distribution compares to his peers. Apparently that strategy has not been enough to stop grade inflation.

The new Princeton proposal would require each department to give no more than 35% A’s (including A+ and A-) in courses. It would be left to each department to decide how to stay under this cap.

I don’t know yet whether I’ll vote for or against this proposal. But I do know that if it passes, my department will have to set some policy for allocating our quota of A’s among our courses. Setting that policy will be no fun at all, even in a department as sane and collegial as mine.

UPDATE (10:45 AM): For more reaction, see today’s Boston Globe story by Marcella Bombardieri.

WIPO Considering a Ban on Computers

Ernest Miller points to a draft treaty being considered by the World Intellectual Property Organization. It’s a truly remarkable document. And I don’t mean that in a good way.

Here’s the most amazing part, from Article 16, Alternative V:

2. In particular, effective legal remedies shall be provided against those who:

(iii) participate in the manufacture, importation, sale, or any other act that makes available a device or system capable of decrypting or helping to decrypt an encrypted program-carrying signal.

Every computer is “capable of decrypting or helping to decrypt” such a signal, so this provision, if adopted, would apparently require signatories to the treaty to ban the importation, sale, or distribution of computers.

Note this this is just an “alternative” under consideration. It was proposed by Argentina, and Switzerland proposed language that “roughly corresponds” to it. I don’t know whether the U.S. has taken a position on this, but I assume the U.S. is still in favor of computers being legal.