# Older blog entries for ladypine (starting at number 30)

11 Dec 2002 (updated 11 Dec 2002 at 18:33 UTC) »
bram, you are right claiming that the exchange of cost and benefit is a delicate point. We each have our own utility function, which is the connection between money and other things. This function indeed may be different with various people, or we might even have a utility from money which is not linear (I would care more about the difference beween a million dollar and nothing, than between one million and two).

But the fact that the utility is something which differs among people, and is secret (you usually cannot tell how much I am *really* willing to pay for that camera which is on auction right now, because my cousin gets them cheap), does not mean that you as an organizer of an auction, has to give in to that.

A first price auction, (sealed bid) is a bad mechanism in that sense: nobody ever proposes what they really think the item is worth, cause they are trying to gain something here. The lower they suggest, the more they gain *if* they win. But take the second prize auction: every user suggests a price, the one who suggested the highest price wins, and gets to but the good. At what price? the price that the second best offer gave. Example: Alice says 5, Bob says 10. Bob wins and pays 5.

Now, the user's best strategy is to tell the truth: his/her real valuation of the good. If the user names a lower price, then somebody might win the good at a price in which the user still gains. And why should the user care about the fact that the sum (s)he says is high? after all, it is not as if (s)he is actually paying it- the real price is set by the second high bid. Of course the user would never say more than her/his real valuation:)

Pareto efficiency is a term of stability. Stability is indeed reached when no small group (one, two, does not matter) can make an alteration to their status, without involving others, and be better off. This only means that this is a *local* optimum. Indeed, greedy algorithms are known to "finish", but what optimum do they give?

There is a whole theory about match making (cooperative games), for example, where a valid match is such that there are no two people (man and woman, in that case. I think the homosexual match making is more complicated) who prefer each other over their current status. Another variant is the match making of (US) medical students to hospitals. In both those similar algorithms, if the people who wish to be matched submit their preferences list, a main server can compute a valid, stable, Pareto efficient matching. The only question is, what matching would that be? The matching scheme that was implemented in the hospital-student algorithm creates the matching that is best for the hospitals and worst for the students. Running the algorithm the other way round yields the opposite outcomes, of course.

In short, Pareto efficiency just means the single person is helpless. An overall view of a server should be able to give better results, but then again the complexity of such an optimization is usually too hard.

artimage, what you are trying to do is design a mechanism. The best source of information I know would be
```@BOOK{mas-colell,
Author="Mas-Collel A. and  M. Whinston and J. Green",
year="1995",
title=" Microeconomic Theory",
publisher="Oxford University Press",
note="Chapter 23: Incentives and Mechanism Design"
}
```

Keep in mind though, that file sharing is something usually done without any monetary transfers, while the method used in game theory to make users (in game theory speak- "agents") act according to some desired behaviour, is to introduce payments into the game. A famous mechanism in which truth telling is a dominant strategy is the Clark- Groves mechanism:

```@ARTICLE{clarke,
AUTHOR="E. Clarke",
YEAR= "1971",
TITLE="Multipart pricing of public goods" ,
JOURNAL="Public Choice",
VOLUME= "18",
PAGES="19-33"
}

@ARTICLE{groves,
AUTHOR="T. Groves",
YEAR= "1973",
TITLE="Incentives in Teams",
JOURNAL="Econometrica",
VOLUME= "41",
PAGES="617-631"
}

```
This mechanism is designed to maximize the sum of utilities of all agents, by choosing an optimal "social choice"- choice which affects everybody. In that mechanism, everybody is paid according to the sum of all the others' utilities (calculated according to their declarations). This way, if you tell the truth according to your utility (say, in an auction, you say how much you really think the item is worth). Then, since the server/organizer is maximizing the sum of utilities, and your overall utility is your real utility plus the others' (declared) utility, your own utility coicides whith whatever the server/organazer is trying to maximize. Hence- tell the truth and count on the server to maximize your *own* utility.
4 Dec 2002 (updated 4 Dec 2002 at 17:39 UTC) »

Some mails are worth the trouble. I am trying to get the weekly newsletter from the local wine and delicassy store in an open format, instead of a *.doc file. Now that I have explained the problem ("No, thank you, I do not want a fax"), they are working on it.

I now remember (not too fondly ) the days of my first degree studies, when I had time for nothing. At least now I do a lot more.

We are trying to meet in order to start the open source Israeli NPO thing going. I think I got a bit over the top, constructing social welfare functions for choosing the best day to meet in. Shachar asked everybody to give a score for their ability to arrive on each day, from 0 for "cant make it" to 2 for "no problem". Shachar wanted to sum them up, and choose the day with the highest score. I offered to choose:

```It is not really a matter of proof, but of a choosing the social welfare
function we wish to optimize. The classical social welfare function of

maxmin (happiness)

does not help here, since in this case all options have the same value: 0.
We need a tie-breaker, which is often picked in game theory as a lottery
among the equal options (according to the social welfare function).
A more reasonable tie breaker would be

calculating for each day:

sad=maxmin (happiness) /*value of happiness of the saddest people, in our case 0*/

chosen_day= argmin (sad_group_size) /*the chosen day is a day which
minimizes the size of the sad group*/

in case argmin (sad_group_size) consists of more than one day, the tie breaker can be a lottery.

```

Can I add this to "You know you've been hacking your thesis too much when..."?

It is kilmo's birthday this week end, according to one of the dates. Happy birthday, Orr!

9 Nov 2002 (updated 9 Nov 2002 at 04:26 UTC) »

In the past week (goes to show how much time I got to write) we have seen the play "Kiss Me Kate", or some other version of "Taming of the Shrew". Amazing how the main actress managed to convey so much disgust and anger in those humble words of the finishing monologe.

On Wednesday we had the Insta-Party/ Linuxday. I missed Aviram and Noam from beyond security, which I am very sorry about, but I could only come in the evening. Both my sister and mulix's sister came, and they enjoyed each other's company if not guy's lecture, which was a very good basic use lecture, only they could hardly hear a thing. There were also some annoying people: people who complained about not getting explanations about that Linux installed on their box, while the basic use lecture was on, and they just did not bother to listen. Or people who complained that the instalation they got was not personally customed, but did not bother to come to the installation lecture.

I was supposed to be muli's assistant in the networking lecture, but I am going to be on holiday instead. I think this holiday also falls on an important lecture in the technion.

Gilad sent us an invitation on Wednesday to be on Thursday evening in Tel Aviv, to sign some papers. I could not make it, and neither could mulix. I still do not know if they signed the papers without us. Maybe I should not get into this business at all.

1 Nov 2002 (updated 1 Nov 2002 at 17:23 UTC) »

Welocme to Linux (1) is over. Both my sisters came, as well as my father, which was quite a surprise to me. He stayed after the lecture, and talked to Oron Peled, a haifux memeber. My sisters got caught in a most interesting conversation with Alon Altman, asking him questions such as: "tell me one bad thing about Linux", and "Why sould anybody develop open source?"

Of course it took far longer than expected, but I managed to make most speakers attend to the time they were alloted. It was a good idea to put Guy last, with the programming example part, cause We began losing people like that. kilmo was very good on stage, as well as mulix. I wonder why it is that those who were so good on stage made it their business to stay there as little as possible.

For the the insta-party I have Omri's laptop Power-PC to install, and this is going to be interesting. In other words- Not easy.

More and more things are demanding my attention. Maybe this is a hint to stop starting new things?

Tomorrow is the welcome to linux lecture which I am hosting. I hope my two kid sisters would come, but we seem to be having transportation problems. mulix 's sister would come, and that's half the job. She is already composing html using emacs. I enjoy so much when I teach intelligent people who wish to learn, but I guess we all prefer to be young anf healty rather than old and sick.

Had a welcome-to-linux (1) rehearsal yesterday. nyh could not come, as well as guy, and mulix took sick. We were left with three speakers except me, which took a lot of time as well. We would never fit it all in the time frame of one hour. The last week has been a mad house between haifux meetings for welcome to linux and rehearsals for "Caramba's Revenge" and trying to do my thesis as well. The cat suffers from lack of attention. I tend to think I am taking too much at once. I guess some people would agree.

4 Oct 2002 (updated 4 Oct 2002 at 22:37 UTC) »

The Haifux lectures are coming together.More specifically, the first one, which I am in charge of. Shlomi Loubaton has already prepared his part, showing great screenshots of linux in hebrew, though it is not finished yet. and i even made the feedback forms. Almost. I must get to understanding html in Hebrew.

mulix will talk about the joy of kernel hacking, and kilmo about the benefits of running a server.

Alon is going to play some games, I hope the crowd would not be bored. It is a hard mission. Guy will write a text editor in ten minutes, and nyh will talk about his essay about free software. All in ten minutes, like meat on a stick.

syscalltrack is at a cross road. The syscalls table has beed unexported, and it is a vital part of the operation of syscalltrack. I am looking forward to learning about the ways other mechanisms use to hijack system calls.I hope there is a way to keep the syscalls table. It was so elegant. But it seems that it is a matter of politics.

2 Oct 2002 (updated 3 Oct 2002 at 19:52 UTC) »

Knesset Discussion

The committee, which discusses computer issues in the Knesset, assembled again today. This time, some of us where there: Gilad Ben Yossef, Doron Ofek, Katriel Traum, Muli Ben Yehuda, Tzafrir Cohen and me. This report is my point of view of the events. (If you want the bottom line, get to the bottom!)

This discussion, as well as the previous one, was held on-line as well as orally. In practice, it means that the speakers were often asked to speak slowly, so that the typist can make it. Technical words had to be considered in advance, or spelled. Every now and then (about five times during the couple of hours we spent there), someone would make a remark regarding the people who were chatting and contributing information in the lower part of a screen, on which the web page was projected. It was certainly felt that the people at home were anxious to get to the open source discussion, and I do not believe the nicknames made such a good impression on the people in the committee.

Actually, the committee was, as Knesset Member Michael Eitan said "just me". After a while of sitting there I realized that the more-or-less 40 people who where there, were either summoned to present to the committee, or came there because they had an obvious interest.

I will skip the discussions which prevailed the open source discussion, and get to what we came there for.

Since in the previous discussion M\$ representatives were not able to answer, due to lack of time, this time they started it. M\$'s Israeli CEO, Arye Skop(sp.?) came this time himself. He was sitting on the side, and was invited to sit in the front panel, and later on was asked to transfer to the middle of the front panel, so that the typist should hear him. Later on, when he wanted to make a point, he put his hand in a most friendly/fatherly manner on Eitan's shoulder and chest, using this position wisely.

He talked about how he started as a developer of software with open source (it was mostly open source in those days, though not GPL). He claimed that the developers who changed the source had the power, since nobody knew what they had done in there. He claimed that M\$ is the cheapest in the sense of TCO (appears to be a leading TLA in this world. Total Cost of Ownership). He said that the the OS is but a mere 3% of the total cost of a project. He said that it is important for customers to work with a firm standard product. (Remember this, a gun in the first act...).

Then came a part where we were mostly hands raised high in the air, but Eitan ignored us completely. Some speakers confused the term open-source with their ability to chose a supplier. Then began a wave of fear from the "open source firms" (The assumption was that open source is a name that unites some firms which are M\$'s competitors)who will force the whole government offices, by legislation, to use their product alone. and still, we could not speak. We sat there, adrenalin pumping in our veins, sometimes even losing our temper all at once when something really offensive was said, not able to speak.

Oracle's CEO understands what open source is, and why it is good to let the customer choose an open source OS, to install his servers on. He explained things, set some order, represented our side, and I noticed him sneaking a look at us in between. At least we got someone to relate to us as "the guys over there"!

Then, finally, Michael Eitan let one of us speak. Gilad took that opportunity, and did a marvelous job. He explained the two points he had to say: 1. What we do in our workplaces and homes can be done in the state's facilities: move at least the servers to open source, step by step, move new systems to open source, and save our taxes.

2. As a citizen with an operating system which is open source (which is what the "Kid From Ofakim" can afford), he demands, as part of the state's intention for giving info to the public, that he should be able to access it. If the Supreme Court presents its decisions in a *.doc format, which is proprietary, he cannot do that. If the site of the Interior Ministry does not support any open source browser, he cannot use this facility.

This is where the gun from the first act showed up. Eitan got to asking Gilad what he proposed to do. Gilad started phrasing the demand for open standards, dictated by an international body, and ended up collaborating with Doron Shikmoni to produce a proposal for a law proposal.

21 older entries...