MacroLink

Macro

MicroMicro

Micro-Macro LinkApproach: Lave & March

Micro-Macro LinkApproach: Lave & March

In ordinary thinking when we have a result to explain, we are usually content to think of some simple explanation and then stop. This is incomplete thinking; it stops before the process is fully carried out.

Micro-Macro LinkApproach: Lave & March

In ordinary thinking when we have a result to explain, we are usually content to think of some simple explanation and then stop. This is incomplete thinking; it stops before the process is fully carried out.

The real fun

Micro-Macro LinkApproach: Lave & March

In ordinary thinking when we have a result to explain, we are usually content to think of some simple explanation and then stop. This is incomplete thinking; it stops before the process is fully carried out.

To continue thinking and see what other ideas the explanation can generate, to ask ourselves: if this explanation is correct, what else would it imply?

The real fun

Lave & MarchModels

a model is a simplified version of the world

Lave & MarchModels

Models are created by speculating about the process that could have produced the observed outcomes

a model is a simplified version of the world

Lave & MarchModels

Models are created by speculating about the process that could have produced the observed outcomes

a model is a simplified version of the world

Models are evaluated in terms of their ability to predict correctly other facts

Lave & March4 steps

1. 2. 3. 4.

Lave & March4 steps

1. 2. 3. 4.Observe

some facts

Lave & March4 steps

1. 2. 3. 4.Observe

some factsSpeculate about the

process that might have produced

such results

Lave & March4 steps

1. 2. 3. 4.Observe

some factsSpeculate about the

process that might have produced

such results

Deduce other results

from the model

Lave & March4 steps

1. 2. 3. 4.Observe

some factsSpeculate about the

process that might have produced

such results

Deduce other results

from the model

Ask if these otherimplications

are true

Lave & MarchExplanation

if this explanation is correct, what else would it imply?

Lave & MarchExplanation

Unexpected Results: if a result was not predicted, other processes must be involved

if this explanation is correct, what else would it imply?

Lave & MarchExplanation

Unexpected Results: if a result was not predicted, other processes must be involved

if this explanation is correct, what else would it imply?

Human not Individual: good models of human behavior are rarely precise interpretations of individual actions

Lave & March3 rules of thumb

Lave & March3 rules of thumb

think “process”

Lave & March3 rules of thumb

think “process”

develop interesting implications

Lave & March3 rules of thumb

think “process”

develop interesting implications

look for generality

Lave & Marcha beautiful model

Lave & Marcha beautiful model

simple

Lave & Marcha beautiful model

simple

fertile

Lave & Marcha beautiful model

simple

fertile

unpredictable

Aims Lecture 3

To explain the relation between the behavior of individual and the social outcomes

1

2 To present how to construct individualistic explanations to social phenomena

inSocial Science

Explanation

Explanationin social sciences

The evaluation of a problem is made to the entire aggregate outcome

Not, merely how each person does within the constraints of his own environment

The principal task of the social sciences lies in the explanation of social phenomena, not the behavior of single individuals

LevelsOf analysis of social phenomena

Examination of the processes internal to the social system, involving its component parts, or units at a level below that of the system

Individual

aggregate

Explaining the behavior of the system by considering the behavior of its parts

Major Problem

The micro-to-macro Problem

Moving from the lower level to the system level

It is present throughout the social sciences

ExampleResidential segregation

Example 1: Residential Segregation

http://www.nrc.nl/nieuws/2012/02/14/statistiek-saai-cbs-cijfers-komen-tot-leven-op-een-kaart/

Proportion of niet-westerse allochtonen (non-western immigrants)

The Netherlands has a particular way to trace in great detail the residential composition: The postal code (four digits + two letters). This reduces the composition to units of about 15 households.

Think: How do you expect to see the map colored

The case of Amsterdam

Example 1: Residential Segregation

There is few well-mixed composition, mainly blue (very western) and red (very non-western)

There is residential segregation

Does high levels of segregation in a city show that people want segregated neighborhoods?

This is an important social phenomenon to be explained

Residential Seggregation

There are political, social, economic implications from it

Can mapping segregation in a city tells us why there is segregation and what can we do about it?

&

Practical 2

ExampleThomas Crombie Schelling

Born in California (USA), 1921

Nobel Economics, 2005 (shared with Robert Aumman)

" For having enhanced our understanding of conflict and cooperation through game theory analysis"

There is residential segregationWhy is there residential segregation?

People are xenophobic, and xenophobic people choose to segregate

Does residential segregation show that people are xenophobic?

http://ccl.northwestern.edu/netlogo/models/Segregation

NetLogo model library - Model: Segregation

What other explanations could there be?

Residential SeggregationSchelling’s

Observe

Speculate

Video

http://www.youtube.com/watch?v=JjfihtGefxk

Residential SeggregationSchelling’s

Even if there are no other mechanisms into consideration (i.e., house pricing, income inequality, and off course preferences)

This can be observed in other places, such as the U.S.

Even if people don’t want to live in segregated neighborhoods it will emerge as a consequence of individual behavior.

Residential Preferences in the USEmpirical Results on

Clark and Fosset, 2008

The individual level: Empirical results on residential preferences in U.S.

Data from “Metropolitan Study of Urban Inequality”

Clark and Fosset, 2008

Their summary:

“The most common response sets for ideal neighborhoods are in the range of majority or near majority same-group presence.”

Data from Metropolitan Study of Urban Inequality

“The most common response sets for ideal neighborhoods are in the range of majority or near same-group presence”

What have we seen?

It is not straightforwards to say that because individuals can be satisfied with integrated neighborhoods, there will be integrated neighborhoods

The interplay of individual actions can bring about, at the social level, something that is not really a one-to-one translation.

Components of the theoryused in explaining social phenomena

3 components

IndependentMacro-variable

DependentMacro-variable

Input individual choice: Choice options Information Costs and benefits...

Output: Individual choice

Macro relationship

Theory of action

Bridge assumptions

Transformation assumptions

1

2

3

as “games”Social Phenomena

Consider a Social-Simulation Game

A set of roles that players take on, each role defining the interests or goals of the player

Social theory represents social problems as the working out of various rules

Rules about the kinds of actions that are allowable for players in each role, as well as about the order of play

Individual Roles

Behavioral Rules

as “games”Social Phenomena

Consider a Social-Simulation Game

Social theory represents social problems as the working out of various rules

Rules specifying the consequences that each player’s action has for other players in the game

Results Rules

of a social system

The game simulates the behavior

Players & the structure of the game

Purposive behavior

(1) Sets in motion the individual actions &

(2) Combines them to produce behavior of the social system

2 Components

Players

The game

Transition 1Macro-to-Micro

All those elements that establish the conditions for a player’s action:

Personal interests (given by the goal established by the rules)

Initial condition (context within which action is taken)

Transition 2Micro-to-Macro

The consequences of the player’s action:

How it combines with, interferes with,

or interacts with

the actions of others

Individual LevelTheory of Action

Rational Choice TheoryNext Lecture

Explanationpurposive behavior

In all the speculations there is a notion that people behave in a way we might call purposive

Goals, purposes or objectives relate directly to other people and their behavior

We have a mode of contingent behavior - behavior that depends on what others are doing

Explanationtheory based behavior

We use considerations of behavior based on theories (i.e., Rational Choice Theory)

But, with people it is a hard task to model their motives

If we consider them as rational maximizers, we might forget sometimes human limitations and exaggerate results.

ExplanationHow to evaluate soc. Phenomena

We use Rational Choice Theory

Infer, from what we take to be the behavior characteristic of people, some of the characteristics of the system as a whole

Deduce some evaluative conclusions

The concept ofEmergence

EmergenceIn Schelling’s model we found segregation even though we did

not assume that individuals did want to live in segregated neighborhoods

Collective phenomena which are unintended in the sense that individuals do not seek to create them, are called

emergent phenomena.

the interplay of individual behavior can create patterns which cannot be directly inferred from motives of the individuals

Example

Think: how do people choose to sit when they come to a conference?

Seating Patterns

Seating PatternsSchelling arrives to give a conference and observes, from what he could see, that the first 12 rows of the auditorium were empty

1

2 Thinking the room was empty, when he came in, noticed that the room was completely full from row 13 on

Think: how did this came about?

Seating Patterns

Think: how did this came about?

First 12 rows

All but first 12 rows

Seating Patterns

Think: how did this came about?

Think: What motivates individual behavior?

First 12 rows

All but first 12 rows

Seating PatternsThink: Is aggregate behavior an extrapolation from the individual behavior?

Seating PatternsThink: Is aggregate behavior an extrapolation from the individual behavior?

LinkMacro

Micro

Micro-Macro LinkIf we know that at sundown every driver turns his lights on, we can guess that from an helicopter we can see all car lights in a local area going at about the same time

a

bBut, if most people turn their lights on when some fraction of the oncoming cars already have their lights on, we will get a different picture from our helicopter

Micro-Macro Link

In B drivers are responding to each other’s behavior. People are responding to an environment that consists of other people responding to their environment, which consists of people responding to an environment of people’s responses.

Micro-Macro Link

No simple summation or extrapolation to the aggregate

Situations in which people’s behavior or people’s choices depend on the behavior or the choices of other people

Seating PatternsUsing: L&M 4 Steps

1

2 speculate

We observe the sitting patternObserve

Seating PatternsUsing: L&M 4 Steps

1

2 speculatea) Everybody likes to seat as close to the rear as possible

b) Everybody wants to seat to the rear of everybody else

c) Everybody is lazy, so they sit close to the entrance***

d) Everybody likes to seat as far as they can from the lecturer

We observe the sitting patternObserve

Seating Patterns

3

4 ask Test the predictions of the model

If (d) is true, then change the position where the lecturer stands

deduce

Seating Patterns

3

4 ask Test the predictions of the model

If (d) is true, then change the position where the lecturer stands

deduce

Think: What if we have competing predictions: say (c) and (d)?

Check List1. We construct models to explain social phenomena that common sense cannot account for

2. Social phenomena are modeled and explained as the interplay between macro and micro variables

3. The macro outcome is usually emergent and thus cannot be observed by simple aggregation

In addition

The examples demonstrate that micro level theories (i.e., rational choice) have the potential to provide information that we might have overlooked had we focused on the collective level only.

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