Direct and indirect network effects: are they equivalent?

Clements, Matthew T. “Direct and indirect network effects: are they equivalent?." International Journal of Industrial Organization 22.5 (2004): 633-645.


Network effects may be either direct or indirect. While many analyses conflate the two, I show that the ways in which direct and indirect effects influence technological standardization are quite different. Some parameter changes have opposite effects in the two models, and some factors which are irrelevant under direct effects are central under indirect effects. Compatibility in particular has a different interpretation and more subtle implications for standardization in the indirect model.

Network effects, Network externalities, Standards, Compatibility

JEL classification

  • L1

Group Performance and Decision Making*

Norbert L. Kerr and R. Scott Tindale (2004) “Group Performance and Decision Making," Annual Review of Psychology. 2004. 55:623–55. doi: 10.1146/annurev.psych.55.090902.142009.


Theory and research on small group performance and decision making is reviewed. Recent trends in group performance research have found that process gains as well as losses are possible, and both are frequently explained by situational and procedural contexts that differentially affect motivation and resource coordination. Research has continued on classic topics (e.g., brainstorming, group goal setting, stress, and group performance) and relatively new areas (e.g., collective induction). Group decision making research has focused on preference combination for continuous response distributions and group information processing. New approaches (e.g., group-level signal detection) and traditional topics (e.g., groupthink) are discussed. New directions, such as nonlinear dynamic systems, evolutionary adaptation, and technological advances, should keep small group research vigorous well into the future.

The Economics of Patents and Copyright

Leveque, Francois and Ménière, Yann, The Economics of Patents and Copyright. MONOGRAPH, Berkeley Electronic Press, July 2004. Available at SSRN:; [PDF]

This ebook is a primer on the economics of intellectual property, meant to be accessible to non-economists. While intellectual property is more than ever at the heart of so-called knowledge economies, it aims to show the contribution that economic analysis can make to the current debates on the increasing role of patents and copyright. It pinpoints the imperfections of the IP system both in the EU and in the US, and discusses possible remedies. The book provides the reader with a general framework of analysis highlighting the economic functions of intellectual property rights. Using this framework, it revisits successively the evolution and specificities of patent law and of copyright law. A final Chapter is devoted to the the interface between intellectual property law and antitrust law. The book contains abundant examples and gives a large place to the findings of empirical economic research. The book is widely used as a textbook in IP law courses.

Number of Pages in PDF File: 61

Keywords: Patent, Copyright, Innovation, Antitrust

JEL Classifications: O3

Distinguishing informational cascades from herd behavior in the laboratory

Distinguishing informational cascades from herd behavior in the laboratory

Bo ̆açhan Çelen and Shachar Kariv (2004) The American Economic Review, 2004 –

… circumstances. While the terms informational cascade and herd behavior are used

interchange- ably in the literature, Lones Smith and Peter N. Sørensen (2000)

emphasize that there is a significant difference between them. …

Smith and Sørensen (2000) emphasize that there is a significant difference between them. An informational cascade is said to occur when an infinite sequence of individuals ignore their private information when making a decision, whereas herd behavior occurs when an infinite sequence of individuals make an identical decision, not necessarily ignoring their private information.

被引用 139 次 – 相關文章 – 全部共 27 個版本; 提供的 [PDF]

Lones Smith and Peter N.Sørensen 2000 – Google 學術搜尋.

A Summary for "Why Experimental Finance?"

By Shyam Sunder, Yale School of Management

International Conference on Experiments in Economic Sciences: New Approaches to Solve Real World Problems

Okayama, Japan, December 14-15, 2004.

這是耶魯大學管院 Shyam Sunder 的演講投影片, 我閱讀理解後所整理的重點摘要與注釋 (不全然是翻譯)。

1. Why Do We Need More Data from Experimental Markets?

Asset markets 中有很多 (交易) 資料, 但是缺乏「預期」(expectations) 的資料, 但這卻是眾多財務理論中重要的假設。另外在實驗中可以在控制的環境中設定 (已知) 的參數 (註: 例如資產報酬風險的大小),以利檢證財務理論。

2. What Can Simple Experiments Tell Us about Complex Markets?

科學的目標即是尋找「簡單的法則」,來預測大部份 (不是全部) 的有趣之真實世界之現象

3. Is This Behavioral Economics/Finance?

經濟 (財務) 實驗強調市場及其他相關制度的設計對交易者之影響,其研究重點是:

  • 制度與規則 (市場微結構 microstructures)
  • 基於已知的資訊,市場參與者如何思考與行動
  • 設計實驗以區別何種理論較符合市場運作現況
  • 便於當做測試不同制度下之風洞試驗場 (test beds)
  • 分析焦點是均衡、效率、價格、和分配
  • 可與「現地實證研究」 (field empirical research) 互補

4. What Have We Learned from Experiments?

實驗運用於財務領域大致是從 1980 年代前後開始 (我印象中也是 Vernon Smith 先開始的),也發掘了一些有趣,不可能單獨從「現地實證研究」中發現的財務市場現象。

Key findings:

  • Security markets can aggregate and disseminate information (efficient markets)
  • But they do not always do so (inefficiency)
  • Information dissemination, when it occurs, is rarely instantaneous or perfect (learning takes time)
  • Markets permit costly research to persist in equilibrium (why pay for research?)
  • Price, as well as bids, offers, timing, etc., transmit information (many channels for information flow)
  • Well-functioning derivative markets help improve the efficiency of primary markets
  • Most important: statistical efficiency or inability to make money from past data does not mean informational efficiency (“can’t make money” does not mean “the price is right”)

Efficient Markets: Information Dissemination

Plott and Sunder (Journal of Political Economy, 1982) established the basic proposition through a simple experiment :

  • Can markets disseminate information from those who know to those who don’t?
  • Could not be established from analysis of field data because we don’t know the distribution of information among investors?


  • Markets can disseminate information from the informed to the uninformed investors
  • Dissemination can occur through trading, without exchange of verbal communication
  • Such markets can achieve high levels of informational efficiency
  • Securities end up in the hands of those who value them most