Mere internet, færre drab og voldtægter

En af de mest interessante og altid underholdende forskere at læse mere populære klummer og kommentarer af er den fabelagtige økonom Steven Landsburg, forfatter til den moderne klassiker og bestseller “The Armchair Economist”.  Som vi tidligere har nævnt her på stedet, så skriver han fast for Slate.com, hvor han giver lænestols-økonomistiske forklaringer på dette eller hint, eller kommenterer andres forskning.  Det er altid læsværdigt, som f.eks. denne klumme, “How the Web Prevents Rape”, fra for et par måneder siden, som er en indirekte opsang til udviklings-pessimisterne, der i internettet kun ser stigende problemer:

“Does pornography breed rape? Do violent movies breed violent crime? Quite the opposite, it seems.

First, porn. What happens when more people view more of it? The rise of the Internet offers a gigantic natural experiment. Better yet, because Internet usage caught on at different times in different states, it offers 50 natural experiments.

The bottom line on these experiments is, “More Net access, less rape.” A 10 percent increase in Net access yields about a 7.3 percent decrease in reported rapes. States that adopted the Internet quickly saw the biggest declines. And, according to Clemson professor Todd Kendall, the effects remain even after you control for all of the obvious confounding variables, such as alcohol consumption, police presence, poverty and unemployment rates, population density, and so forth.

OK, so we can at least tentatively conclude that Net access reduces rape. But that’s a far cry from proving that porn access reduces rape. Maybe rape is down because the rapists are all indoors reading Slate or vandalizing Wikipedia. But professor Kendall points out that there is no similar effect of Internet access on homicide. It’s hard to see how Wikipedia can deter rape without deterring other violent crimes at the same time. On the other hand, it’s easy to imagine how porn might serve as a substitute for rape.

If not Wikipedia, then what? Maybe rape is down because former rapists have found their true loves on Match.com. But professor Kendall points out that the effects are strongest among 15-year-old to 19-year-old perpetrators—the group least likely to use such dating services.

Moreover, professor Kendall argues that those teenagers are precisely the group that (presumably) relies most heavily on the Internet for access to porn. When you’re living with your parents, it’s a lot easier to close your browser in a hurry than to hide a stash of magazines. So, the auxiliary evidence is all consistent with the hypothesis that Net access reduces rape because Net access makes it easy to find porn.

Next, violence. What happens when a particularly violent movie is released? Answer: Violent crime rates fall. Instantly. Here again, we have a lot of natural experiments: The number of violent movie releases changes a lot from week to week. One weekend, 12 million people watch Hannibal, and another weekend, 12 million watch Wallace & Gromit: The Curse of the Were-Rabbit.

University of California professors Gordon Dahl and Stefano DellaVigna compared what happens on those weekends. The bottom line: More violence on the screen means less violence in the streets. Probably that’s because violent criminals prefer violent movies, and as long as they’re at the movies, they’re not out causing mischief. They’d rather see Hannibal than rob you, but they’d rather rob you than sit through Wallace & Gromit.

I say that’s the most probable explanation, because the biggest drop in crime (about a 2 percent drop for every million people watching violent movies) occurs between 6 p.m. and midnight—the prime moviegoing hours. And what happens when the theaters close? Answer: Crime stays down, though not by quite as much. Dahl and DellaVigna speculate that this is because two hours at the movies means two hours of drinking Coke instead of beer, with sobering effects that persist right on through till morning. Speaking of morning, after 6 a.m., crime returns to its original level.

What about those experiments you learned about in freshman psych, where subjects exposed to violent images were more willing to turn up the voltage on actors who they believed were receiving painful electric shocks? Those experiments demonstrate, perhaps, that most people become more violent after viewing violent images. But that’s the wrong question here. The right question is: Do the sort of people who commit violent crimes commit more crimes when they watch violence? And the answer appears to be no, for the simple reason that they can’t commit crimes and watch movies simultaneously.

Similarly, psychologists have found that male subjects, immediately after watching pornography, are more likely to express misogynistic attitudes. But as professor Kendall points out, we need to be clear on what those experiments are testing: They are testing the effects of watching pornography in a controlled laboratory setting under the eyes of a researcher. The experience of viewing porn on the Internet, in the privacy of one’s own room, typically culminates in a slightly messier but far more satisfying experience—an experience that could plausibly tamp down some of the same aggressions that the pornus interruptus of the laboratory tends to stir up.

In other words, if you want to understand the effects of on-screen sex and violence outside the laboratory, psych experiments don’t tell you very much. Sooner or later, you’ve got to look at the data.”

Kan man lide denne slags analyser, bør man naturligvis heller ikke undlade at læse David D. Friedman.

8 thoughts on “Mere internet, færre drab og voldtægter

  1. TerminalFrost

    Med andre ord skaber internetporno og voldelige biograffilm positive eksternaliteter. Vil det sige at disse burde få statsstøtte? ;)Jeg burde erhverve mig Armchair Economist, om ikke andet så for at få et fyldigt svar på, hvorfor koncertbilletpriser ikke er højere. Freakonomics var ikke nær så god, som den var hypet til at være (hvilket du også har givet udtryk for).

    Svar
  2. Peter Kurrild-Klitgaard

    Jeg mangler fortsat–og jeg har spurgt dusinvis af økonomer–en god forklaring på, hvorfor biografbilleter/sæder i USA fordeles efter “først til mølle”-princippet, altså uden prisdiskriminering, mens de herhjemme sælges i kategorier efter pris. Det virker påfaldende, at USA–et af de mest markedsøkonomiske lande–anvender samme rationeringsprincip i denne del af markedet, som Air Cubana gør ved flysæder … (Konsekvensen er, at man i USA skal stå i kø eller sende en tidligere afsted for at reservere sæder–altså sådan lidt østeuropæisk.) Jeg har indtil videre fået den ene dårlige forklaring efter den anden–eller ihvertfald irrationelle.

    Svar
  3. JR

    Glimrende indlæg. Analysen af mordratens afhængighed af voldelige film lider dog af den svaghed, at den kun analyserer ekstremt kortvarige effekter. Effekter på længere tidsskalaer siger den ikke noget om.

    Svar
  4. Lars Hvidberg

    Det lyder som en sjov undersøgelse. Det er jo sådan noget, medieforskningen har kæmpet med i årtier med psykologiske forsøg m.m. Der skulle altså lidt økonomi med ind over…Men kan det i øvrigt passe, at voldsmænd ikke vil se Wallace & Gromit? Der er da også masser af action!

    Svar
  5. David G

    Jan: I England står folk ikke stille på rulletrapper. Eftersom folk der står stille på rulletrapper driver mig til vanvid har jeg i årevis søgt at forklare hvorfor de dog gør det i Danmark og USA når man i England kan finde ud af at bruge rulletrapper til deres formål, som dog må være at komme hurtigere (ikke langsommere) op eller ned. Den “typiske” rulletrappeadfærd er kun typisk i visse lande. Hvorfor?

    Svar
  6. Peter Kurrild-Klitgaard

    Rulletrapper: Jeg hader selv, når folk står stille på rulletrapperne–ihvertfald i venstre side og dermed både blokerer og viser, at de er nogle uberejste bonde…. Netop derfor har jeg undret mig over forskellene fra land til land. (Jeg har dog forskellig opfattelse af USA, David; jeg mener, at amerikanerne generelt har en fortræffelig rulletrappe-kultur …)Og så en dag læste jeg en artikel med en forsker–vistnok i “Ud & Se” (?), der faktisk havde undersøgt det. Det viser sig, at i f.eks. USA/UK blev rulletrapper indført/udbredt primært i lufthavne, på banegårde o.l.–hvor folk har travlt. I DK var det derimod i første omgang i Magasin, Dalle Valle og senere i lignende indkøbsmagasiner–hvor det blev opfattet som lidt af en luksus snarere end en nødvendighed.Med andre ord skulle danskernes uciviliserede anvendelse af rulletrapper i Kastrup, på Hovedbanen og alskens større provinsbanegårde være udtryk for en slags (mit udtryk) “kulturel path-dependency” … 😉

    Svar
  7. Jan Madsen

    Kurrild,Du behærsker buzz-words som en sand handelshøjskole professor. Kommer du aldrig over til os på CBS?Interessant undersøgelse i øvrigt.David,Det irriterer også mig grænseløst. Jeg har dog endnu ikke oplevet noget så slemt som det her:http://liberator.dk/brog/?p=88

    Svar

Skriv et svar

This site uses Akismet to reduce spam. Learn how your comment data is processed.