The First DraftDetails

J. M. Pogodzinski

Outline

• Introduction

• Literature Review

• Model

• Testable Implications

• Data

• Empirical Methods

• Conclusions

• Summary

11/24/2014 J. M. pogodzinski 2

Introduction

• Say what the paper is about• Say why this is important• What is your contribution? (Data, model,

method, interpretation?)• Say how the paper is organized• Should you give away the secret – two kinds of

detective novels– Who dun it? Sherlock Holmes– Police procedural – how did they catch him? (E.g., The

Laughing Policeman: A Martin Beck Police Mystery by Maj Sjowall and Per Wahloo

11/24/2014 J. M. pogodzinski 3

Example(Flat Earth)

In this paper I will show that the Earth is flat. It is important to know this so we can avoid falling off the edge.

In the next section I will review literature about the shape of the earth, pointing out where much of the literature is flawed.

I will then construct a model of the Earth (MKF Model) and derive testable hypotheses from the model.

I will then gather data and apply appropriate statistical tests to determine whether the Earth is flat.

The last section is a summary and conclusion.

11/24/2014 J. M. pogodzinski 4

Literature Review

• Narrative

• How does the literature relate to your paper– Adapted or adopted

• The model

• The data

• The empirical method

– Literature in conflict on• The model

• The data

• The empirical method

11/24/2014 J. M. pogodzinski 5

Example(Flat Earth)

Galileo, Newton, and Copernicus were all wrong! These guys had a bunch of data from telescopes. But telescopes distort the image.

11/24/2014 J. M. pogodzinski 6

The Model

• What are you trying to explain?• What abstractions do you employ?

– E.g., trying to explain the population of a central city in a metropolitan area

– Central City, suburbs, public good, cost function, scale economies represented by fixed cost

– Costless mobility of households

• Is there anything special or notable about your abstractions?– E.g., Always have scale economies– Fixed population of metro area– Different numbers of suburbs

11/24/2014 J. M. pogodzinski 7

The Model(Flat Earth)

I develop a model of the Earth called My Kitchen Floor (MKF).

11/24/2014 J. M. pogodzinski 8

Testable Hypotheses

• If the model is true, what does this mean about what we will see in the real world

• For example, the Urban Fiscal Model implies that (holding other factors constant) having more suburban locations is associated with a smaller Central City population

• Can discuss why this might hold

11/24/2014 J. M. pogodzinski 9

Testable Hypotheses(Flat Earth)

• Rolling a marble across my kitchen floor will result in marbles that roll straight – i.e., their deviation from a straight line will be small

• Therefore, distance should not matter when explaining accuracy, i.e., distance should not be significant in explaining accuracy

11/24/2014 J. M. pogodzinski 10

Data

• For your paper identify for each variable the

– Source

– Level of aggregation

– Time period covered

– Geographical coverage

– Number of observations

11/24/2014 J. M. pogodzinski 11

ExamplePanel Data on School Districts and Municipalities

• School site– Located within municipality and school district– Open or closed in the period 2007-2012

• API– School level variable

• Geographic coverage: California• Time period: 2007-2012• Number of observations

– Schools – approximately 6,000– School districts – approximately 1,000– Municipalities – approximately 400

11/24/2014 J. M. pogodzinski 12

Example(Flat Earth)

11/24/2014 J. M. pogodzinski 13

Plot of Data

11/24/2014 J. M. pogodzinski 14

0

5

10

15

20

25

30

35

40

-1.5 -1 -0.5 0 0.5 1 1.5

distance (in inches)

Empirical Methods(Flat Earth)

11/24/2014 J. M. pogodzinski 15

Empirical Methods(Flat Earth)

11/24/2014 J. M. pogodzinski 16