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November 18, 2004

Yamamoto(2004)

Hitoshi Yamamoto and Kazunari Ishida and Toshizumi Ohta, "Modeling
Reputation Management System on Online C2C Market", Computational &
Mathematical Organization Theory, Vol.10, pp.165-178, 2004.
論文ゼミのT岡物件．
なんか問題意識に対して，論文でのアプローチや結果が，それを解決するものではないような気がする．

This paper discusses the effectiveness of sharing
information concerning the reputations of buyers and sellers making
online transactions in a consumer-to-consumer (C2C) market. We
developed a computer simulation model that describes online
transactions with a reputation management system that shares
information concerning the reputations of consumers. The model takes an
agent-based approach in which agents' action are based on the iterated
prisoner's dilemma. No model exists to analyze C2C markets even though
there are many case studies concerning the effectiveness of sharing
reputation information among participants in a market.
(pp.165)

The e-commerce market is growing rapidly, thanks in part
to the ease at which participants can enter and exit, it's anonymity
and ease of registration. However, these attractive features have led
to a new problem, which is increasing risk of cheating in online
trading, e.g., receiving goods without payment or receiving payment
without sending goods, as there are incentives to get goods or payments
without being forced to make corresponding the contribution.
(pp.165)

上でいっていることについて，下ではyahooやe-bayがいい感じに対応しているといっているが，どうなんだ．とてもうまくいっているようには思えませんが．
だからエクスローとかと併用システムを採用していると思うのですよ．

However, several online auctions, e.g., eBay and Yahoo
auction, have effectively supported C2C transactions. Based on these
successful examples, we hypothesize that sharing information concerning
one's reputation is important to managing the risk of cheating in C2C
online transactions.(pp.166)

この考え方は，one-shot的状況を仮定して，ちょっと裏切ってexitするような行動について考慮できないものであることは明らか．
そして不正の元もこのような行動であることも明らか．

If the acquaintance has high profits from that market, the
new agent begins to carry out actions in the market. In contrast, if
the acquaintance has low profits, the newcomer avoids the market. Bryne
(1965) showed that a person gets acquainted with other persons who have
similar attitudes and characters. In our model, therefore, a new
participant selects the best current strategy in the market.
(pp.171-172)

figure 7では，不正が10%程度に減っていることが示されているが，10%って大きい数字だと思いますが．
利用者の10%が料金を支払わなかったり，商品を送らないオンライン取引っていやだ．

From figure 7, we see that if a market can evaluate
positive behavior, it can make a cooperative strategy dominant. In
other words, it is effective in promoting cooperation in addition to
penalizing non-cooperative behavior.
(pp.176)

もうちょっと他にやり方があるのではないかと思う次第．

Posted by ysk5 at November 18, 2004 10:50 PM