February 15, 2018

QotD: Computer models

Filed under: Economics, Quotations, Technology — Tags: , , — Nicholas @ 01:00

How can one be certain about outcomes in a complex system that we’re not really all that good at modeling? Anyone who’s familiar with the history of macroeconomic modeling in the 1960s and 1970s will be tempted to answer “Umm, we can’t.” Economists thought that the explosion of data and increasingly sophisticated theory was going to allow them to produce reasonably precise forecasts of what would happen in the economy. Enormous mental effort and not a few careers were invested in building out these models. And then the whole effort was basically abandoned, because the models failed to outperform mindless trend extrapolation — or as Kevin Hassett once put it, “a ruler and a pencil.”

Computers are better now, but the problem was not really the computers; it was that the variables were too many, and the underlying processes not understood nearly as well as economists had hoped. Economists can’t run experiments in which they change one variable at a time. Indeed, they don’t even know what all the variables are.

This meant that they were stuck guessing from observational data of a system that was constantly changing. They could make some pretty good guesses from that data, but when you built a model based on those guesses, it didn’t work. So economists tweaked the models, and they still didn’t work. More tweaking, more not working.

Eventually it became clear that there was no way to make them work given the current state of knowledge. In some sense the “data” being modeled was not pure economic data, but rather the opinions of the tweaking economists about what was going to happen in the future. It was more efficient just to ask them what they thought was going to happen. People still use models, of course, but only the unflappable true believers place great weight on their predictive ability.

Megan McArdle, “Global-Warming Alarmists, You’re Doing It Wrong”, Bloomberg View, 2016-06-01.

January 26, 2018

British sex workers create a “National Ugly Mugs” database to avoid sketchy customers

Filed under: Britain, Business, Technology — Tags: , , , , , — Nicholas @ 03:00

At The Register, Iain Thomson reports on a study of professional sex workers in Britain:

A study into the effect of the internet on professional sex workers has shown the online world keeps them safer, happier in their job, and more able to weed out creepy customers.

Researchers at the universities of Leicester and Strathclyde in the UK interviewed 641 courtesans – with a roughly 80/20 per cent female to male split – and found [PDF] more than three quarters found using online channels to find and vet punters made them safer in their trade. Online forums also gave then a valuable tool in staying safe and countering loneliness or depression.

“Girls are very open because obviously we started talking about the safety from the very get-go,” Milena, 32, an independent escort providing BDSM services. “If you didn’t have that internet … everything would have been underground and everybody would be scared.”


“I’d say the worst bit of the job is constantly feeling like you’ve got to look over your shoulder,” said Jane, 40, a BDSM specialist. “Even though I’m working legally, I’m constantly worried.”

Sex workers in the UK have also set up a National Ugly Mugs database, whereby abusive punters are flagged up by their email addresses or social media handles, which 85 per cent of the respondents used. Sharing this information between themselves made is much less likely that the workers would come to harm.

Support groups for people in the business have been greatly enabled by the online world.

Prostitution is legal in the UK, but not in a brothel or via a pimp. Going online meant that 89 per cent of respondents used online communications to eliminate the need for a third party to manage their affairs, 82 per cent went online to make sure they weren’t breaking the law, and 78 per cent said it had improved the quality of their lives.

June 27, 2011

“A substantial expansion of the FBI’s power to monitor innocent Americans”

Filed under: Government, Law, Liberty, USA — Tags: , , — Nicholas @ 12:06

Julian Sanchez on the changes to the FBI’s domestic rulebook:

The change in the rules will remove a crucial deterrent for any of the 14,000 FBI employees who might be tempted to use their government access to all kinds of databases for improper personal ends, or to flout rules prohibiting religious, racial and political profiling. This is no hypothetical concern: Shortly after the new guidelines were announced, a former CIA official alleged that the Bush administration had asked the spy agency to dig up dirt on academic and blogger Juan Cole, whose fierce criticism of the war in Iraq earned the ire of the White House.

The new manual will also give agents who have opened assessments greater authority to employ physical surveillance teams. If the FBI thinks you might make a useful informant, agents will be free to dig through your garbage in hopes of finding embarrassing trash that might encourage you to cooperate. And they will be able to do this without first having to show any evidence that you are engaged in wrongdoing.

The FBI, predictably, is downplaying the changes in its rulebook, characterizing them as “clarifications” and “tweaks.” But all these tweaks add up to a substantial expansion of the FBI’s power to monitor innocent Americans — power Congress wisely curtailed in the 1970s in light of the bureau’s ugly history of spying on political dissidents. The law set broad limits on the most intrusive investigative techniques, such as wiretaps, but the details of who could be investigated and how were largely left to executive branch regulation. As statutory restraints on surveillance have been peeled back over the last decade, Americans have been asked to rely more than ever on those internal rules to check abuses.

August 13, 2009

Sorry for the downtime this morning

Filed under: Administrivia — Tags: — Nicholas @ 09:46

My new host had some problems with the database connections this morning, resulting in a loss of access to the blog (both for you and for me . . . I couldn’t get access on the admin side either). Service appears to be back to normal now.

If you didn’t notice a problem, feel free to ignore this post.

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