Dynamic Foraging Model for Human Behavior on the internet (working title)

1. Dynamic Foraging Model for Human Behavior on the internet (working title) Bjarne Berg

2. Agenda Introduction and Background Optimal Foraging Theory (OFT) Foraging Models Economic perspective (EMH and REH) Human Factors Proposed Framework Question and Answers

3. Background Despite extensive research in the human evolution since 1854 when Charles Darwin published his thesis on the Origin of the Species, the motivation and the behavior associated with foraging and thereby the natural selection through the survival of the best foragers, was not well researched for over one hundred years. This changed in 1966 when researchers such as Emlem published his work on the foraging behavior of birds and by the publication the same year of MacArthur & Pianka’s work on the individual’s selection process of foraging areas. Over the next thirty years this research gave rise to a large field known as Optimal Foraging Theory (OFT) that has been the foundation in a variety of biological and zoology studies. Only in the last ten years OFT has been extended into the field of information technology and search algorithms (Sugawara and Watanabe, 2002; Pui and Huosheng, 2002).

4. Background At the same time, there has been an increased interest in the last decade of extending OFT into a better understanding of human behavior on the internet through intelligent foraging agents (Jiming et. al., 2004) and through extensions to social behaviors of foraging agents (Andrews, 2007). Most of this research has focused on optimizing the algorithms of robots or intelligent agents that can, on behalf of the human, scan vast amounts of information to find specific items.

5. Agenda Introduction and Background Optimal Foraging Theory (OFT) Foraging Models Economic perspective (EMH and REH) Human Factors Proposed Framework Question and Answers

6. The Optimal Foraging Theory (OFT) In 1966 the field known as Optimal Foraging Theory (OFT) was established through the publication of Emlen’s article on foraging behavior of birds and by MacArthur & Pianka’s work on optimization models the same year. In general, the models established over the next ten years focused on four core areas that became known as elements of a micro-ecological theory. These areas include 1) What to eat (optimal diet). 2) Where to eat (optimal patch choice). 3) Optimal allocation to each patch (time). 4) Optimal patterns and speed of movements. Combined as a whole, the micro-ecological theory forms the platform for macro-ecological theory which has far reaching implications

7. The Optimal Foraging Theory (OFT) Natural Selection – The optimal should already be here Cost- Benefit and minimal benefit requirements Optimal Patch Choice (OPC)– scholastic models (bird’s patch selection) Committed exclusions and logical progressions Sub-optimal foraging – social and cultural constraints Compression Hypothesis - as the number of competing species increase, a reduction in the patches used occur & the range of items consumed remains constant or only slightly increase . Specialization – Koala Bears (increased food abundance leads to greater food preference)

8. Agenda Introduction and Background Optimal Foraging Theory (OFT) Foraging Models Economic perspective (EMH and REH) Human Factors Proposed Framework Question and Answers

9. Foraging Models Optimal Diet Theory (ODT) - also includes advanced mechanisms for gradual shifts in item acquisitions when preferable items (high net benefit) exists or becomes more abundant. Optimal Time Allocation (OTA) and Marginal Value Theorem (Chernov, 1976), and Surrender Time Evolutionary foraging algorithms The simplest approach to account for the dynamically changing environment has been to introduce uncertainty/variability into the approach and rebuild the new optimal search patterns and speed of movements each time a foraging event on a patch, or set of patches, are completed (Yang & Yao, 2005). This was a focus area in the OFT research field in the late 1990s and 00s. The number of recent models proposed using this approach are numerous (Branke, 2002; Jin & Branke, 2005; Tin´os & Yang, 2005).

10. Evolutionary Foraging Algorithms (EA) • Bacterial foraging algorithms (BFA) and Dynamic BFA (DBFA) • Group foraging theory and diversity in Evolutionary algorithms • Dynamic and Memory enhanced foraging algorithms (E. Coli) • Thermodynamical Genetic Algorithm (TDGA)

11. Agenda Introduction and Background Optimal Foraging Theory (OFT) Foraging Models Economic perspective (EMH and REH) Human Factors Proposed Framework Question and Answers

12. EMH and REH • Efficient Market Hypothesis • Rational Expectance Hypothesis • Price Dispersion and 2-step models

13. Agenda Introduction and Background Optimal Foraging Theory (OFT) Foraging Models Economic perspective (EMH and REH) Human Factors Proposed Framework Question and Answers

14. Human Factors

15. Agenda Introduction and Background Optimal Foraging Theory (OFT) Foraging Models Economic perspective (EMH and REH) Human Factors Proposed Framework Question and Answers

16. Constructs The task of the seller is to minimize the consumer surplus, while the task of the consumer is to maximize it. It is important to note that if there are no consumer surplus, the sale cannot occur (consumers would be unwilling to proceed). Therefore some consumer surplus has to exist, however marginal. In a foraging model an implicit equilibrium should exists between the consumer price, the foraging costs and the foraging surplus on one side and the optimal (best price available) and the incremental foraging costs of locating this best price.

17. Constructs

18. Time Constructs

19. Foraging Costs and Incremental Foraging Costs

20. Foraging Search Costs

21. Overall model (work in progress)

22. Example - calculations

23. Some hypothesis

24. Some hypothesis

25. Your Turn! How to contact me: Bjarne Berg bergb@lr.edu