Forgot your password?
typodupeerror
GNU is Not Unix Media Television

Open Source at TiVo 226

Posted by michael
from the small-price-to-pay dept.
CowboyRobot writes "ACM Queue has an article by TiVo co-founder Jim Barton, in which he explains how the company relies on open source technologies to create a closed-source product. A good lesson in how other companies can do the same. From the article: Careful management of our sources to abide by the terms of the GNU General Public License while protecting our proprietary developments is a small price to pay for this benefit."
This discussion has been archived. No new comments can be posted.

Open Source at TiVo

Comments Filter:
  • Nice one Jim ... (Score:3, Insightful)

    by craigmarshall (679127) on Friday August 22, 2003 @05:12PM (#6768830)
    >in which he explains how the company relies on open >source technologies to create a closed-source product ... but haven't Microsoft been doing this for years with the BSD source code? -- Craig
  • Quick, someone erase this article, BEFORE SCO SEES IT! (yes, its a joke)
    • Yes, this was intended to be funny. However, SCO wanted a $32 license fee per embeded device. This includes the TiVo and the Sharp Zaurus PDA.

      Considering I haven't seen too many dual-processor TiVo units, I really don't understand how SCO thought that was legit, but then again, nothing else they want seems legit.

  • by Broadband (602443) on Friday August 22, 2003 @05:13PM (#6768838)
    I applaud Tivo for showing such appreciation for open source publically. As more and more companies hail the benifits of open source we might see even more developers do so, both lowering development costs and supporting more platforms. Both which are good for consumers. I myself am wedged so far into Microsoft territory that I cannot budge and every application we use for our industry is 100% Microsoft product requirements, whether it be windows or internet explorer. Hopefully continued publicity like this will improve the knowledge of alternative solutions.
    • I myself am wedged so far into Microsoft territory...

      Got Butter?
  • Interesting quote (Score:3, Interesting)

    by JohnGrahamCumming (684871) * <slashdot@nosPam.jgc.org> on Friday August 22, 2003 @05:13PM (#6768840) Homepage Journal
    This use is somewhat controversial. Advocates of the GPL and the Free Software Foundation interpret the GPL more stringently to disallow the use of proprietary modules. On the other hand, Linus Torvalds has stated that proprietary loadable modules are acceptable.
    Wonder if they'll ultimately be forced to release this code? Anyone know if the FSF has expressed an opinion on this? John.
    • by smartin (942) on Friday August 22, 2003 @05:19PM (#6768895)
      Wonder if they'll ultimately be forced to release this code? Anyone know if the FSF has expressed an opinion on this?
      The FSF would be fools to force such an issue. Tivo is trying to work with the system as well and maintain their advantage over their competators. Jerking them around with the GPL would simply drive them and others away, thats not what we want, (right RMS?)
      • The FSF would be fools to force such an issue. Tivo is trying to work with the system as well and maintain their advantage over their competators. Jerking them around with the GPL would simply drive them and others away, thats not what we want, (right RMS?)

        I do agree with you, but sense hasn't stopped the FSF from spending an awful amount of effort telling everyone that they must say GNU/Linux instead of Linux. I wonder why Linus doesn't just come up with a license of his own that makes it clear what y
        • he has, it's called the GPL with use of the exceptions clause. The exceptions clause is the portion of the GPL where you can put in your own changes such as binary modules.

        • The GPL is very clear on what you can and cannot do with Linux. Can you justify otherwise? (Please don't answer that if you work for SCO.)
        • by Anonymous Coward
          GPL-hater handbook, technique number 23: Bringing up "GNU/Linux" in a discussion about the GPL to discredit RMS and/or the GPL.

          RMS' _request_ that people use the term GNU/Linux has absolutely nothing to do with the GPL. Yeah maybe it makes him look foolish but he has the right to _ask_ for whatever he likes.

          This is different than the GPL which is a legal document. You *must* abide by the GPL or you violate copyright law in a pretty clear way.

          Linus can't do much about the license now because 1) he has to
      • by jbn-o (555068) <mail@digitalcitizen.info> on Friday August 22, 2003 @05:56PM (#6769176) Homepage
        The FSF would be fools to force such an issue. Tivo is trying to work with the system as well and maintain their advantage over their competators. Jerking them around with the GPL would simply drive them and others away, thats not what we want, (right RMS?)

        I'm not RMS, nor do I speak for him, the FSF, or any of the Linux kernel copyright holders. However, you appear to misunderstand a significant point about the development of the GNU Project and GNU/Linux in particular. There's nothing foolish about requiring compliance with the generous GNU General Public License, particularly nothing foolish about insisting that people cooperate in the commons the GNU GPL builds for us all. Nobody is more important than anyone else in this partnership (including Tivo). It is Tivo's job, not ours, to find a way to make money with GPL-covered programs if that is their desire.

        Perhaps you aren't aware that the GNU Project (and the continued development of the GNU/Linux operating system in particular) is not about achieving mere popularity at the expense of user's freedom to share and modify. From this essay [gnu.org]:

        People justify adding non-free software in the name of the "popularity of Linux"--in effect, valuing popularity above freedom. Sometimes this is openly admitted. For instance, Wired Magazine says Robert McMillan, editor of Linux Magazine, "feels that the move toward open source software should be fueled by technical, rather than political, decisions." And Caldera's CEO openly urged users to drop the goal of freedom and work instead for the "popularity of Linux".

        Adding non-free software to the GNU/Linux system may increase the popularity, if by popularity we mean the number of people using some of GNU/Linux in combination with non-free software. But at the same time, it implicitly encourages the community to accept non-free software as a good thing, and forget the goal of freedom. It is no use driving faster if you can't stay on the road.

        And this essay [gnu.org]:

        Proprietary software developers, seeking to deny the free competition an important advantage, will try to convince authors not to contribute libraries to the GPL-covered collection. For example, they may appeal to the ego, promising "more users for this library" if we let them use the code in proprietary software products. Popularity is tempting, and it is easy for a library developer to rationalize the idea that boosting the popularity of that one library is what the community needs above all.

        But we should not listen to these temptations, because we can achieve much more if we stand together. We free software developers should support one another. By releasing libraries that are limited to free software only, we can help each other's free software packages outdo the proprietary alternatives. The whole free software movement will have more popularity, because free software as a whole will stack up better against the competition.

    • by cperciva (102828) on Friday August 22, 2003 @05:21PM (#6768911) Homepage
      Wonder if they'll ultimately be forced to release this code?

      They won't. One of the major principles of contract law is that if a contract is confusing, the confusion is resolved in favour of the party which did not write or choose the contract.

      Given that there's widespread disagreement about how far "GPL taint" extends, I'm pretty sure that any dispute here would be resolved in favour of the loadable modules not needing to be released.
    • by vondo (303621) * on Friday August 22, 2003 @05:21PM (#6768914)
      I think it's more rigorous that "Linus says its OK." I think the license for the Linux kernel is officially GPL+"binary loadable modules are OK" so the kernel is not strictly under the GPL.
      • Re:Interesting quote (Score:4, Informative)

        by JohnGrahamCumming (684871) * <slashdot@nosPam.jgc.org> on Friday August 22, 2003 @05:26PM (#6768956) Homepage Journal
        If you visit kernel.org you'll find the following license (the COPYING [kernel.org] file) in /pub/linux/kernel [kernel.org].

        It is the GPL v2 with the following preamble:

        NOTE! This copyright does *not* cover user programs that use kernel
        services by normal system calls - this is merely considered normal use
        of the kernel, and does *not* fall under the heading of "derived work".
        Also note that the GPL below is copyrighted by the Free Software
        Foundation, but the instance of code that it refers to (the linux
        kernel) is copyrighted by me and others who actually wrote it.

        Linus Torvalds

        Doesn't seem to be anything other than user level code mentioned here, I guess we must assume that TiVo's modifications are user level.

        John.
        • Actually, if you read the article, you'll see that he mentions that when he talks about how their hardware is proprietary and they want to use closed drivers. The issue is the non GPLed kernel modules, if I read things correctly.

        • Re:Interesting quote (Score:4, Informative)

          by topham (32406) on Friday August 22, 2003 @07:09PM (#6769683) Homepage
          Tivo uses modules and signatures to protect their IP.

          binary modules are allowed; and by using a boot PROM which verifies the kernel has a valid signature they can be sure the kernel is approved by them. (Series 2 units with the latest kernels are extreemly difficult to hack in the same way as the first units.).

          Linus at some point specificly mentioned that doing a signature check was outside of the scope of the Linux kernel copyright and GPL license. So Tivo is on the up-and-up. Even if it upsets some people.

    • by OECD (639690) on Friday August 22, 2003 @05:22PM (#6768918) Journal

      Anyone know if the FSF has expressed an opinion on this?

      It's implied:

      This use is somewhat controversial. Advocates of the GPL and the
      Free Software Foundation interpret the GPL more stringently to disallow the use of proprietary modules. On the other hand, Linus Torvalds has stated that proprietary loadable modules are acceptable.
      (emphasis mine) That's from section 7 of the article, BTW.

      Wonder if they'll ultimately be forced to release this code?

      The GPLed source is here [tivo.com]

  • Cool! (Score:3, Funny)

    by yotto (590067) on Friday August 22, 2003 @05:14PM (#6768846) Homepage
    Maybe now they'll sue the people who wrote the code they used!
  • by tambo (310170) on Friday August 22, 2003 @05:14PM (#6768849)
    Why do they have any incentive to be "careful" about their use of open-source? Why not just paste it into your proprietary, closed-source application? It's closed-source, so the chances that anyone finds out are slim to nil. Of course, you have to maintain that as the company line...

    Indeed, given the "business ethics? we've heard of 'em" nature of business these days, carefully shepherding one's source code to respect open-source rights is a losing value proposition. It takes resources - time, employees' attention, assignment of responsibility, meetings - while helping the company avoid a terrifically small chance of a lawsuit. Not the *right* thing to do, by any means, but probably the *customary* thing to do.

    I've been wondering quite a lot recently just how much respect closed-source developers typically afford to open-source code. I think the answer is a dirty little secret of the software biz.

    - David Stein
    • One disgruntled ex-employee as a whistleblower could screw with the whole company. It's easier just to let people have the source.

      Espescially in TiVos case. It's not like you can realistically build your own TiVo anyways. The embedded software is an extremely minor component of the system as a whole.

      Businesses arent as evil and corrupt in general as some would have you believe. They're run by people, in the end.
      • Been in the business world a long time? ;)

        OK, serious response.

        First, general philosophy: History has show, consistently, that trusting corporations to do the right thing is a terrifically bad idea. Especially when it's more costly/troublesome than doing the wrong thing. Especially when the chances that they'll get caught, or punished, are insignificant. I needn't remind you that both Ken Lay and Martha Stewart still walk the streets as a reminder of this.

        Now, practical response: Whistleblowers? Are you
        • It's another thing altogether to ruin your career because your employer stole some open-source wonk's implementation of the cosine function.

          I'm not attacking you. But, every damn time I call "copyight infringement" "stealing" thousands of wannabe /. lawyers jump on my ass. And here you get away with it.

          Cmon, where are all the "copyright infringement isn't stealing" people? Why is it ok to label illegal use of FLOSS as stealing, but not illegal downloading of music?

          (BTW, that was a rhetorical question a
    • Keeping the source closed only helps MS take over more of the communication world. "What are we doing today BILLY BRAIN.....Writing a new closed source version of our Windows O$ of course Binky!"
      How the hell can companies like MS make a living if they cannot clone things like Unix code and then make all of their added IP proprietary? Just think they have had one hell of a time replacing their hotmail servers with an NT clone so the chances are that they really are trying to go it alone with NT4,5,6 just by
    • I have encountered GPL'd code in proprietary software I was hired to work on. I immediately removed it from the project (like, within minutes), and did my damndest to get the coder that put it in there fired (that part ended up being delayed because he was in the middle of becoming a she...).

      I think most proprietary, closed-source developers - at least any halfway decent ones - are going to have a similar reaction. See, any closed-source programmer worth his or her salt is going to value copyright laws (

      • Satan's Librarian (581495) said:

        I have encountered GPL'd code in proprietary software...immediately removed it, did my damndest to get the coder...fired...delayed because he was in the middle of becoming a she...

        --------------

        Sir, you were late with the justice; The universe has already punished this poor soul more harshly than you could ever hope to.

        Look up "gender reassignment surgery", and tell me that it isn't punishment enough for this crime against the GPL.

        • True. She was going through hell. I've known others who have gone through that procedure, too - although in one of the cases I think the damage was far worse to the guy's daughter than it was to him.

          However, it's not profitable for a company to have their entire coding staff having to chase someone through the code to know that a.) it works, and b.) it isn't stolen. And, the GPL problem predated the announcement of the process.

  • Readable version (Score:3, Informative)

    by cperciva (102828) on Friday August 22, 2003 @05:15PM (#6768856) Homepage
    Maybe it's just MSIE being wierd, but the story appeared in a really small font.

    The "printable version" [acmqueue.org] is far easier to read.
  • by joeldg (518249) on Friday August 22, 2003 @05:17PM (#6768877) Homepage
    Most companies, if they can, will use 100% open source to create totally closed-source solutions. The exceptions being the 100% microsoft shops, and those guy have all their profits eaten up by licenses, and "of course" they won't open source anything because the licenses restrict that they "can't". (I at one time worked as an ASP programmer and am happily a three-years now PHP programmer).

    The old point was, pay for a product, you pay for support; however, this is not true anymore (just try and call MS technical support without having a license you pay $1000 for).. But something like MySQL or PHP you can easily and quickly get help in any forum..

    But I digress.. the point is, most "smart" companies do this to keep costs down.
  • by bobsalt (575905) on Friday August 22, 2003 @05:28PM (#6768973)
    was jsut browsing though dishnetwork.com and saw that they offer the software(minus some prop. stuff) fro thier PVR model

    http://208.45.37.181/


    • Minus some prop. stuff? That's a bit of an understatement, dontcha think?

      It's just the kernel plus a few things standard utilities - i.e. the bare minimum they're required to make available. *None* of their own userland software is available, same as Tivo [tivo.com].
  • Nits (Score:5, Interesting)

    by crumley (12964) * on Friday August 22, 2003 @05:38PM (#6769034) Homepage Journal
    I love my TivO, and I thought that the article was pretty interesting, but I think I found a couple of small problems with it.
    Still-famous companies entered the GNU/Linux distribution business: Red Hat, VA Linux, Slackware, and others.
    As I recall, VA Linux never had their own Linux distribution. The started out selling hardware with Linux pre-installed, grew too quickly into other areas, and then crashed.
    Public domain soft-ware. This is software that has been made available for any use, with no restrictions. Many public domain packages are available, the most notable of which are the X Window System and BSD operating system.
    While I can see how a category such as Barton's "public domain software" could be useful, I think that he has named it very poorly. There is are crucial differences between software that is in public domain, which has no copyright, and BSD software. Public domain software can whith a few alterations be claimed by anyone as there own, while the copyright notices withing BSD software must not be removed. Of course, you can still do pretty much anything you want with BSD software, other than claim it as your own.
    • Re:Nits (Score:2, Informative)

      by DrSmooth (22080)

      As I recall, VA Linux never had their own Linux distribution. The started out selling hardware with Linux pre-installed, grew too quickly into other areas, and then crashed.

      Having signed for more than my fair share of VA Linux hardware deliveries, I can confirm that they did, indeeed, have their own distribution (in the loosest sense).

      The distro was based off of RedHat, carried the same revision numbers as RedHat, but came on VA-labeled media with VA-specific software for server administration.


      % ca

  • by 514x0r (691137) on Friday August 22, 2003 @05:41PM (#6769065)
    rather than sending jobs to india, lowering TCO is the way to go. as more companies--ie, ernie ball and now tivo--hail the benefits of open source the movement gains momenteum. eventually there will be a[nother] tech revolution......

    bring it on.
  • Why the GPL? (Score:3, Interesting)

    by evilviper (135110) on Friday August 22, 2003 @05:49PM (#6769127) Journal
    Can anyone tell me... If they are going to create a closed-source product, why did they go the Linux route, instead of using (Free/Net/Open)BSD?

    I am at a real loss to tell what the advantage is... In a non-embedded environment, it's reasonable, because you want to support the greatest ammount of hardware as possible. But with an embedded system, they only need support for one TV-capture card, one video card, one network card, etc. They aren't using any stock Linux software, it's all custom.

    In fact, the things they say were needed in the article, (performance, stability, good vm) are unarguable better in the BSDs.

    So why do they use Linux? Not trying to troll, just wondering what advantage it really has in such an embedded system.
    • WEll, TiVo actually supports a couple dozen network adaptors (it doesn't come with one). But I don't get why that would be enough reason by itself. Seems more likely that was just what more people knew when they started out, and they certainly wouldn't want to change now.
    • Re:Why the GPL? (Score:3, Insightful)

      by rusty0101 (565565)
      I would suspect that a large portion of the reason is that there was quite a bit of hardware in the box that at the time had no support in BSD.

      One of the major complaints I was hearing for several years about BSD is that if you had hardware that was not supported out of the box (display cards, sound cards, printers, etc.) you were pretty much left to write your own drivers. I am pretty sure that this is not completely the case now, but it was the general feel I got from the people I knew using BSD.

      TV Tune
      • I would suspect that a large portion of the reason is that there was quite a bit of hardware in the box that at the time had no support in BSD.

        WHAT BOX? There was no box until they made it, and there was only the hardware in it that they chose to put in it.

        One of the major complaints I was hearing for several years about BSD is that if you had hardware that was not supported out of the box (display cards, sound cards, printers, etc.) you were pretty much left to write your own drivers.

        You say it like

    • Same reason everybody else uses embedded Linux instead of BSD: more widely available driver and protocol support.
  • hmmm (Score:4, Funny)

    by SomeOtherGuy (179082) on Friday August 22, 2003 @05:53PM (#6769151) Journal
    My TivO -- One more machine I better make sure I write that $699.00 check to SCO for.

    Damn there goes next weeks lunch money.
  • An interesting bit (Score:5, Interesting)

    by Merk (25521) on Friday August 22, 2003 @05:55PM (#6769163) Homepage
    The TiVo Client Device is of necessity a closed system. As a service provider, we must prevent theft of service, so TiVo pays a great deal of attention to security of the device and resistance to hacking. Additionally, we sell the TCD at a price that provides a net margin to retailers, but no profit to us. Our profits come from providing service to each device over time, rather than from up-front costs.

    I think it is interesting that TiVo says they pay a lot of attention to the security of the device. That is true now, but with the first TiVo devices, getting a BASH prompt on the device turned out to be relatively easy. On boot a menu was available on the serial port with a hardcoded password. Using that password you could make all kinds of changes to the way the machine started up.

    He also metions talks about people getting around using the service. For years, the TiVo hacking community has known how to partially emulate the service by creating slice files and manually loading them onto the device. Recently hackers have figured out how to get an unmodified TiVo to use a service emulator. What's interesting about these development efforts is that they are not putting TiVo out of business.

    In the article, he makes no mention of the goodwill that TiVo has fostered with their users, even their hackers. Soon after TiVo was created, Richard Bullwinkle, their former "Chief Evangelist" started talking to people on bulletin boards. He was always very helpful and forthcoming, with only minor exceptions. He wouldn't talk about bypassing the TiVo service and he wouldn't talk about extracting video from the device. If you didn't talk about those things, he was perfectly happy to help out. Although TiVo was in business to make money through their service, they didn't screw over people who didn't want to subscribe [buffalo.edu]. That's such a treat from a for-profit company. Imagine Microsoft, who also sells their set-top device at a loss, treating customers who don't want to use theirs for gaming without hostility.

    When Andrew Tridgell [anu.edu.au], (the same guy who created Samba and rsync) figured out how to create TiVo slice files so he could use the machine in Australia, it was probably this goodwill which made him choose to not release the info to the general public. Instead, it remained a closely guarded secret.

    Today, years later, the people who have followed in Tridge's footsteps, have refused to destroy TiVo's revenue stream. They have been very careful to try to make sure that only people who can't get TiVo service in their area are allowed to get around it.

    I think the goodwill that TiVo has is partly because of their general attitude towards their customers (and towards the hacker community) and partly the fact they used open-source software, and followed the license requirements. And, it is this, not their security measures, which have ensured that they've maintained a revenue stream -- despite using the "razor and razor blades" pricing model.

    I just wish Mr. Barton hadn't used a loaded term "service theft" to describe people who are using their TiVos without subscribing to the service. That term would be appropriate if people were downloading TiVo data without having a subscription, but not people who are simply choosing not to subscribe and are finding alternatives.

    • He also metions talks about people getting around using the service. For years, the TiVo hacking community has known how to partially emulate the service by creating slice files and manually loading them onto the device. Recently hackers have figured out how to get an unmodified TiVo to use a service emulator. What's interesting about these development efforts is that they are not putting TiVo out of business.

      Why would it?

      Friend: Hey, that's a nice thing what is it?
      Geek: Oh it's my modified TiVo... i
    • Today, years later, the people who have followed in Tridge's footsteps, have refused to destroy TiVo's revenue stream. They have been very careful to try to make sure that only people who can't get TiVo service in their area are allowed to get around it.

      The TiVo hacker community has always done this out of respect for TiVo. We like the product and service, and they had always treated hackers well. They never tried to shut down hacker boards, and in return, the boards don't allow information about theft

  • Huh? (Score:3, Insightful)

    by rudy_wayne (414635) on Friday August 22, 2003 @05:58PM (#6769196)
    >> "13$ a month is more than fair to watch tv on their own schedule, as opposed to having to sit down at prime time"

    Gee, I've been doing that with my VCR since 1984.

    • by karnal (22275)
      You know what's funny? I have said that exact same thing...

      I have a very good friend of mine who recently (6 months) purchased DirecTV and the DirecTivo... Well, he never used to watch tv, but now, he's catching more and more of his favorite shows...

      I would say that Tivo is very good for people who want to see shows and don't want to have to track the times themselves... However, I would lay claim that anything that makes you watch more tv is probably a bad thing... oh well, all things in moderation :)
    • >> "13$ a month is more than fair to watch tv on their own schedule, as opposed to having to sit down at prime time" Gee, I've been doing that with my VCR since 1984.

      Well, it is $13/month versus your time. Your time to keep track of which show is on which tape, to rewind/FF to the beginning of the right show, to figure out how to tape over shows you watch and so forth. Your comment is like an really old-time PC user saying "why would I want a disk drive when I can save to cassette tape?" It i

  • by eyepeepackets (33477) on Friday August 22, 2003 @06:20PM (#6769349)
    I said it in 1996, I'll say it again:

    "Keep the tools open and free: Make your money from developing applications."

    Mr. Butler and company have done well following this philosophy.

    Great article too.
  • Tivo applies this mantra really well. They sell their hardware and their software with a very thin margin, and make their profit from the service. The modules thing seems to me like a detail, but whoever has the copyright of the kernel has the last world. As Linux and most kernel developers say it is OK for Tivo to do that, there is no problem.
  • by jbn-o (555068) <mail@digitalcitizen.info> on Friday August 22, 2003 @06:55PM (#6769588) Homepage

    The article gets some concepts profoundly wrong when it comes to discussing licensing (which is at the heart of the article). These items may confuse readers not already familiar with copyright law and the Free Software community.

    Toward the bottom of the article "Public domain soft-ware [sic]" is mentioned and the "X Window System and BSD operating system" are cited as "notable" examples. Then the article mentions a "license limitation" that is only true for the old BSD license. This clearly illustrates the author is confused about what the public domain is and that works cannot be both licensed (as these examples are, under different but largely similar licenses) and in the public domain. Placing a work in the public domain is not a license, no matter how liberal the license's terms may be. Putting a work into the public domain is the irrevocable abdication of all copyright power over the work.

    The terms "Linux" and "GNU/Linux" are used interchangeably, as if they both refer to the same thing (early in the article "Linux" is meant to refer to an operating system, later on "GNU/Linux" refers to an operating system). The GNU Project asks (and simple fairness requires) that we give GNU a fair share of the credit for their work in the GNU/Linux operating system. Technical precision requires us to distinguish between the Linux kernel and a GNU/Linux operating system. To these ends, the GNU Project publishes a FAQ [gnu.org] on the issue of naming GNU/Linux, and an older essay [gnu.org].

    Finally, just to be clear, the Open Source and Free Software movements are not the same. They have different philosophies, they began at different times, they were started by different people, and they speak to different audiences. The GNU Project's essay on the two movements and their social implications [gnu.org] is helpful.

  • here in the UK. Sky is plugging their Sky+ box like mad, it costs the same per month to subscribe as my TiVO and yet it can only record 'some' series, has only 20 hours of capacity with no chance of hacking it, and reports from owners I have spoken to show that it is very unreliable. Nor does it have wishlists, suggestions and all the other cools stuff that TiVO offers.

    I wish Sky had chosen to go with TiVO for their box, and I wish others would do the same. Why must they always create their own poor imi

The economy depends about as much on economists as the weather does on weather forecasters. -- Jean-Paul Kauffmann

Working...