# Economics of Networks

## Syllabus

## Plan

The plan is exact as to due dates of work from you, and a best guess of our progress through the material.

## Announcements

April 6, 2023: There is no class meeting on Wednesday, April 12. Instead, students are required to attend the theory workshop presentation by Evan Sadler (L070 at 3:30pm).

## Materials

## Lectures

### Lecture 1 (Mar. 28)

- Go over syllabus
- Discuss three vignettes. [notes]

### Lecture 2 (Mar. 29)

- Continue discussing three vignettes
- DeGroot lecture, part 1 [notes]
- The reading for this is Golub and Sadler (2016), 3.1.1, 3.1.2, 3.2 up to the end of 3.2.2
- SS Section 1.4 and Chapter 4 (skip 4.2.3) provide basic background
- Deeper technical background can be found in Carl D. Meyer’s Matrix Analysis and Applied Linear Algebra — see pdf of Chapter 8 for an extract of some of the essential material

### Lecture 3: Math background (Apr 3)

- Selected topics from SS 1.2 and 1.4, as summarized in these rough notes

### Lecture 4 (Apr 5)

- DeGroot lecture, part 2
- Perron-Frobenius theorem, basics of “general centrality theory”
- Read SS Ch. 4 and Golub and Sadler Section 3

### Lecture 5 (Apr 10)

- Introduction to network formation

### Lecture 5A (Apr 12)

### Lecture 6 (Apr 17)

- Conclusion of network formation
- Introduction to linear-quadratic network games

### Lecture 7 (Apr 19)

- Linear-quadratic network games: In-class lab

### Lecture 8 (Apr 24)

- Student lectures
- Abhijit Banerjee, Arun G Chandrasekhar, Esther Duflo, Matthew O Jackson (
*REStud*2019). Using gossips to spread information: Theory and evidence from two randomized controlled trials [slides] - Stephen Morris (
*REStud*2000). Contagion. [slides]

- Abhijit Banerjee, Arun G Chandrasekhar, Esther Duflo, Matthew O Jackson (

### Lecture 9 (Apr 26)

### Lecture 10 (May 1)

- Production networks

### Lecture 11 (May 3)

- Elliott and Golub (JPE 2019)
- Production networks

### Lecture 12 (May 8)

### Lecture 13 (May 10)

- Platforms (remaining material)
- Branching processes, introduction: Based on EK Ch 21, mainly 21.8.A
- Introduction to random graphs

### Lecture 14 (Apr 15)

### Lecture 15 (Apr 17)

- Wrapping up random graph theory
- Student presentations