本研究在網路信任模型中加入間接互惠機制，過去文獻指出名聲在間接互惠的重要性，代理人確保自己能有好名聲下，必須建立良好的信譽，與其他受託人保持合作才能在財富累積上有正的影響。在此模式運行下，觀察代理人們在間接互惠機制下如何運作，是否能順利的配對，進而形成更大的網路拓撲，影響財富創造與分配；透過蒐集第三方的資訊，使得建立連結機制更生活化，代理人獲得訊息並不是隨機的，而是透過動態的社會網路所建立的。
在我們的賽局裡，網路形成過程中信任扮演重要角色，本文考慮的信任是一種短視信任，並以間接互惠機制方式，影響社會網路的形成。代理人(委託人)會依據本身上一回合的資本增減，來決定下一回合要增加連結或斷掉連結。若要建立新的連結，需先挑出一位潛在連結再依據代理人的朋友(受託人)給出的評價，綜合朋友與自己的評價決定是否與潛在連結建立網路，而訊息來源的朋友數量是隨機給定。接著代理人需決定投資與回饋金額，代理人會根據前一期的回報來有效的分配他的投資組合，使用logit模型分配需給予委託人們多少回饋。
實驗發現，在短視的社會下，代理人間較不容易建立信任，對經濟成長、財富分配有負面的影響；在建立連結上，詢問愈多朋友、得到愈多資訊，代理人間建立連結的機率下降，降低財富累積速度，尤其在低技術水準下。在互信的社會資本乘數愈高，吉尼係數愈小，相較於不互信的社會，不論資本乘數大小，社會上一直存在貧富不均的問題。

This study adds an indirect reciprocity mechanism to the network-based trust model. Literatures have pointed out that the importance of reputation in indirect reciprocity. In order to secure a good reputation, agent must not only establish a good reputation but also continuously cooperate with other trustees to accumulate wealth. In this model, we observe how agents interact under the indirect reciprocity and whether agents can be paired successfully therefore to form a larger network topology affecting wealth creation and distribution. This model makes the connection mechanism closer to real life situation by introducing the act of collecting third-party information into the interlinking process. The agent's information access is not random but built through a dynamic social network.
  In the process of trust game, trust plays an important role. Following the definition of existing literature, the trust mentioned in this paper is called myopic trust. It influences the formation of social networks in indirect reciprocity. According to the increasing or decreasing of the capital in the previous round, the agent (trustor) will decide whether to build or eliminate the link in the next round. The decision of building a link is partially based on the rating of that potential link from the agent’s friends (trusted). We then combine friends and agent’s rating to decide whether to build a network with the potential link. The message from agent’s friends is given randomly and then the agent needs to decide the amount of portfolios and feedbacks. According to the return of the previous period, the agent will effectively allocate his investment portfolio and use the logit model to allocate how much feedback to their trustors.
The results show, in the society of myopic trust, the agents are less likely to establish trust with others and this has a negative impact on economic growth and wealth distribution. As for the building of connection, the more the friends an agent inquires, the lower the chances of building of connection and the lower the rate of accumulation of wealth, especially at a low technology level. In the society of myopic trust, the social capital multipliers are negatively related to the Gini index. On the contrary, regardless of the size of the capital multiplier, wealth-inequality is present in the society.

第1章 緒論	1
1.1前言	1
1.2本文架構	3
第2章 文獻回顧	4
2.1信任賽局(trust game)	4
2.2八卦(gossip)	5
2.3信譽(reputation)	6
2.4直接互惠(Direct reciprocity)	7
2.5間接互惠(indirect reciprocity)	8
2.6與未來研究相關之文獻	8
第3章 模型與實驗設計	10
3.1受託人的選擇	13
3.1.1建立連結	13
3.1.2減少連結	17
3.2投資決策	17
3.3回饋	18
3.4短視信任(myopic trust)	19
3.5參數設置	19
第4章 模擬結果	21
4.1技術進步(α)	26
4.2相對互惠(λ)	28
4.3吉尼係數(勞倫茲曲線)	29
4.3.1資本乘數之影響	29
4.3.2 Poisson分配之影響	30
4.4群聚係數與Poisson分配	33
第5章 結論和未來研究方向	37
5.1結論	37
5.2研究發展建議	38
參考文獻	40



表 1 實驗參數設計表	20
表 2 實驗結果第一部份	21
表 3 實驗結果第二部份	22
表 4 實驗結果第三部份	23
表 5 實驗結果第四部份	24


圖 1 潛在連結之集合	14
圖 2 受託人之計分圖	16
圖 3 APL計算示意圖	25
圖 4 技術與社會資本之關係圖	26
圖 5 金融資本增長圖	27
圖 6 組合24之d、K折線變化圖	28
圖 7 組合24之d、K散佈圖	28
圖 8 組合13-16-19-22 (左)、15-18-21-24 (右)平均勞倫茲曲線	30
圖 9 組合1-13-25-37 (左)、4-16-28-40 (右)平均勞倫茲曲線	31
圖 10 組合7-19-31-43 (左)、10-22-34-46 (右)平均勞倫茲曲線	31
圖 11 組合3-15-27-39 (左)、6-18-30-42 (右)平均勞倫茲曲線	32
圖 12 組合9-21-33-45 (左)、12-24-36-48 (右)平均勞倫茲曲線	32
圖 13 組合1-13-25-37 (左)、10-22-34-46 (右)平均群聚係數	35
圖 14 組合3-15-27-39 (左)、12-24-36-48 (右)平均群聚係數	35

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