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Overview. Deliberative DemocracyThe Social Choice CritiqueArrow's TheoremA
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1. Hard Choices in Deliberative Democracy David Gray
Department of PhilosophyCarnegie Mellon University
2. Overview Deliberative Democracy
The Social Choice Critique
Arrow’s Theorem
A “Standard” Response
Relax Universal Domain
A Better Response
Reject Pair-Wise Comparisons
Embrace Interpersonal Cardinal Utilities
A “New” Model of “Rational Decision Making” Deliberative democrats must seriously address results in the social decision science
Arrow’s Theorem is one particularly viable result
Thus far, deliberative democrats have sought to demonstrate how deliberation weakens certain assumptions
For instance, Universal Domain in Arrow’s Theorem
Nevertheless, there are alternatives involving a stronger break with canonical social choice theories
Reject pair-wise comparisons
Implicit in standard preference orderings (complete, transitive)
Embrace interpersonal cardinal utilities
Examine an alternate model of rational decision makingDeliberative democrats must seriously address results in the social decision science
Arrow’s Theorem is one particularly viable result
Thus far, deliberative democrats have sought to demonstrate how deliberation weakens certain assumptions
For instance, Universal Domain in Arrow’s Theorem
Nevertheless, there are alternatives involving a stronger break with canonical social choice theories
Reject pair-wise comparisons
Implicit in standard preference orderings (complete, transitive)
Embrace interpersonal cardinal utilities
Examine an alternate model of rational decision making
3. Tools for E-Democracy at Carnegie Mellon University The notion of a deliberative opinion poll (vs. a standard opinion poll)
PICOLA – Public Informed Citizens On-Line Assembly
Going to be used in January, 2004 on America’s Role in the WorldThe notion of a deliberative opinion poll (vs. a standard opinion poll)
PICOLA – Public Informed Citizens On-Line Assembly
Going to be used in January, 2004 on America’s Role in the World
4. Deliberative Democracy Citizens deliberate over those social policies and laws affecting them Citizens gather to actively discuss, examine, and ultimately select the social policies and laws affecting themCitizens gather to actively discuss, examine, and ultimately select the social policies and laws affecting them
5. Deliberative Democracy When deliberation ends a choice must be made for what policy or law should be adopted Eventually, however, deliberation must end, and the final choice be made for what policy or law should be adopted
When the result accurately reflects the “will of the people”, then we have a legitimate outcomeEventually, however, deliberation must end, and the final choice be made for what policy or law should be adopted
When the result accurately reflects the “will of the people”, then we have a legitimate outcome
6. Deliberative Democracy This involves aggregation… This will inevitably involve some form of aggregation of the preferences of the participantsThis will inevitably involve some form of aggregation of the preferences of the participants
7. The Social Choice Critique There are serious challenges for aggregation
Aggregation mechanisms, such as voting, are inherently flawed
No legitimate aggregation method
Only hope – “vote the bastards out”
Our tools must be able to deal with these challenges Results in the social decision sciences become extremely relevant
They recognizes importance of aggregating preferences in democratic theories
They pose serious challenges for aggregation
Different methods ? Different results
So what is the “will of the people”??
Can we ever have legitimate results?? (And know it)
Our tools must be able to deal with the challenges social choice theories pose for the value of democratic processes
They argue how aggregation mechanisms, such as voting, are inherently flawed
The best we can hope for is to “vote the bastards out” (William Riker, Liberalism versus Populism)Results in the social decision sciences become extremely relevant
They recognizes importance of aggregating preferences in democratic theories
They pose serious challenges for aggregation
Different methods ? Different results
So what is the “will of the people”??
Can we ever have legitimate results?? (And know it)
Our tools must be able to deal with the challenges social choice theories pose for the value of democratic processes
They argue how aggregation mechanisms, such as voting, are inherently flawed
The best we can hope for is to “vote the bastards out” (William Riker, Liberalism versus Populism)
8. Arrow’s Theorem No aggregation mechanism can satisfy:
Completeness and Transitivity
Universal Domain (U)
Weak Pareto Principle (P)
Independence of Irrelevant Alternatives (I)
Non-Dictatorship (D) Impossible for any aggregation mechanism to satisfy relatively simple conditions:
Complete and Transitive
Universal Domain (U)
Weak Pareto Principle (P)
Independence of Irrelevant Alternatives (I)
Non-Dictatorship (D)Impossible for any aggregation mechanism to satisfy relatively simple conditions:
Complete and Transitive
Universal Domain (U)
Weak Pareto Principle (P)
Independence of Irrelevant Alternatives (I)
Non-Dictatorship (D)
9. The Deliberative Democratic Response Deliberation contests some of Arrow’s assumptions
For instance, (U) is denied
“Claro!” vs. “Public Reasons”
Certain rankings are not permitted, because in deliberation participants:
Identify relevant attributes
Prioritize them
The individual preference orderings are shaped accordingly This argument comes from John Dreyzek and Christian List
Deliberation weakens the several of the assumptions of Arrow’s Theorem
In particular, (U) is relaxed
“Public Reasons” must be able to justify an ordinal ranking
Deliberation eliminates the possibility of certain rankings
In deliberation the relevant attributes of the options can be identified
Multi Criterion/Attribute Decision Making
Each participant has an ordering of the options with these preferences
Then the participants agree on what attributes outweigh others
They can mold their overall preference orderings into a shape with single-peaked preferencesThis argument comes from John Dreyzek and Christian List
Deliberation weakens the several of the assumptions of Arrow’s Theorem
In particular, (U) is relaxed
“Public Reasons” must be able to justify an ordinal ranking
Deliberation eliminates the possibility of certain rankings
In deliberation the relevant attributes of the options can be identified
Multi Criterion/Attribute Decision Making
Each participant has an ordering of the options with these preferences
Then the participants agree on what attributes outweigh others
They can mold their overall preference orderings into a shape with single-peaked preferences
10. The Deliberative Democratic Response If participants come with rankings that are “multi-peaked”…
11. The Deliberative Democratic Response Deliberation may cause their preferences to become “single-peaked”
12. The Deliberative Democratic Response Duncan Black’s Result – There will be a pair-wise majority winner and a social ordering Duncan Black’s result shows that whenever the orderings can all be graphed with single peaks, then there will be an acceptable social ordering (a condorcet winner)Duncan Black’s result shows that whenever the orderings can all be graphed with single peaks, then there will be an acceptable social ordering (a condorcet winner)
13. Evaluation of this Response Strength
Facilitates multi-attribute decision making
Weaknesses
Too Ambitious
Will orderings always become single-peaked?
Will participants become clearer about their preferences?
Too Weak
Could orderings become multi-peaked?
Could participants become more confused?
It is not sufficient Strength
Discourse allows participants to identify and share the relevant attributes of the issue
Weaknesses
Too Ambitious
Expects interests to become single-peaked
Assumes participants will become clearer about their preferences
Too Weak
Cannot prevent interests from becoming multi-peaked
Cannot prevent participants from becoming confused about their preferences
It is UnderdevelopedStrength
Discourse allows participants to identify and share the relevant attributes of the issue
Weaknesses
Too Ambitious
Expects interests to become single-peaked
Assumes participants will become clearer about their preferences
Too Weak
Cannot prevent interests from becoming multi-peaked
Cannot prevent participants from becoming confused about their preferences
It is Underdeveloped
14. The Need to Change Assumptions The denial of (U) is dubious
Other options are available
Relax deeper assumptions
Pair-Wise Comparisons
Non-Interpersonal Cardinal Utilities While deliberation’s relaxing of (U) is dubious at best, there are other options available
It is feasible to relax deeper assumptions behind Arrow’s Theorem
Pair-Wise Comparisons
Non-Interpersonal Cardinal UtilitiesWhile deliberation’s relaxing of (U) is dubious at best, there are other options available
It is feasible to relax deeper assumptions behind Arrow’s Theorem
Pair-Wise Comparisons
Non-Interpersonal Cardinal Utilities
15. Arrow’s Theorem Completeness and Transitivity
Pair-Wise Comparisons
Universal Domain (U)
Pair-Wise Comparisons
Independence of Irrelevant Alternatives (I)
Pair-Wise Comparisons
Non-Interpersonal Cardinal Utilities Universal Domain depends on orderings which are based on completeness and transitivity
For (I), see article by SenUniversal Domain depends on orderings which are based on completeness and transitivity
For (I), see article by Sen
16. The Need to Change Assumptions Do not have to hope that deliberation changes preferences – and in a ‘good’ way – to relax (U)
Instead, assume that deliberators might already have a rich appraisal of their options, which relaxes (U) Do not have to hope that deliberation changes preferences – and in a ‘good’ way – to relax (U)
Never have any guarantee this will happen
Instead, assume that deliberators might already have a rich appraisal of their options, which relaxes (U)
Pair-wise comparisons unnecessarily discards potential information in their judgments
Do not have to hope that deliberation changes preferences – and in a ‘good’ way – to relax (U)
Never have any guarantee this will happen
Instead, assume that deliberators might already have a rich appraisal of their options, which relaxes (U)
Pair-wise comparisons unnecessarily discards potential information in their judgments
17. A Paradoxical Individual An American fiscal conservative, hawk
Three options for rebuilding post-war Iraq:
A UN led initiative
A NATO led initiative
Setting up a USA controlled Puppet Regime Consider an American fiscal conservative, war-hawk considering three options for rebuilding post-war Iraq:
A UN led initiative
A NATO led initiative
Setting up a USA controlled Puppet Regime
Consider an American fiscal conservative, war-hawk considering three options for rebuilding post-war Iraq:
A UN led initiative
A NATO led initiative
Setting up a USA controlled Puppet Regime
18. A Paradoxical Individual Get the following a pair-wise choices
UN over NATO
NATO over Puppet Regime
Puppet Regime over the UN
Yet given the three options, he chooses the UN option When considering these options in a pair-wise manner he:
Favors UN over NATO
Favors NATO over Puppet Regime
Yet, favors a Puppet Regime over the UN
Yet when faced with all three options, he chooses the UN optionWhen considering these options in a pair-wise manner he:
Favors UN over NATO
Favors NATO over Puppet Regime
Yet, favors a Puppet Regime over the UN
Yet when faced with all three options, he chooses the UN option
19. A Paradoxical Individual How is this possible?
Is he hopelessly irrational?
What is in the options that pair-wise comparisons are missing?
20. Conflicting Presidential Orders A fiscal conservative, hawk
Considering three options:
UN led initiative
USA led initiative
NATO led initiative
21. Conflicting Presidential Orders A fiscal conservative, hawk
Considering three options:
UN led initiative
USA led initiative
NATO led initiative
22. Conflicting Presidential Orders A fiscal conservative, hawk
Considering three options:
UN led initiative
USA led initiative
NATO led initiative
23. Conflicting Presidential Orders As a conservative hawk, he wishes to know the costs to the US and the relative expansion of US power with each option
As president, he is also somewhat concerned what his nation thinks, so he is provided with data to help him rank optionsAs a conservative hawk, he wishes to know the costs to the US and the relative expansion of US power with each option
As president, he is also somewhat concerned what his nation thinks, so he is provided with data to help him rank options
24. Conflicting Presidential Orders Chooses the NATO option
Argues it is the “2nd Best” option available
25. Conflicting Presidential Orders NATO will not participate
Presented with another option
On pair-wise comparisons, it ranks the same as NATO
Setting up a USA backed Puppet Regime It turns out that NATO cannot participate in rebuilding Iraq
The president’s staff present him another option, which (on pairwise comparisons, ranks the same)It turns out that NATO cannot participate in rebuilding Iraq
The president’s staff present him another option, which (on pairwise comparisons, ranks the same)
26. Conflicting Presidential Orders As a conservative hawk, he wishes to know the costs to the US and the relative expansion of US power with each option
As president, he is also somewhat concerned what his nation thinks, so he is provided with data to help him rank optionsAs a conservative hawk, he wishes to know the costs to the US and the relative expansion of US power with each option
As president, he is also somewhat concerned what his nation thinks, so he is provided with data to help him rank options
27. Conflicting Presidential Orders Chooses the USA option
Argues that the Puppet Regime was the “2nd Worse” option available
28. Conflicting Presidential Orders Chooses NATO Chooses USA option Notice that if we have only pair-wise comparison data available, there is no reason that he should not choose Puppet Regime in the second case…Notice that if we have only pair-wise comparison data available, there is no reason that he should not choose Puppet Regime in the second case…
29. Conflicting Presidential Orders How is this possible?
If he first picks NATO option then he ought to Puppet Regime option
Is he hopelessly irrational?
What are the pair-wise comparisons missing? Okay, okay… I know a trained chimp is most likely more rational than this chump, but just play along with me…Okay, okay… I know a trained chimp is most likely more rational than this chump, but just play along with me…
30. What is to be done? What if these people are perfectly rational?
Pair-wise comparisons seem to be missing out on vital information
Dethrone pair-wise comparisons!
31. An Alternative Model for Rational Decision Making Rational decision making when values conflict over an option and the values themselves cannot resolve the conflict
Reject pair-wise comparisons
Adopt cardinal rankings
Allow interpersonal cardinal utilities Isaac Levi in Hard Choices provides an account of rational decision making under unresolved conflict
Conflicts which occur when individual values cannot agree on a course of action
Reject pair-wise comparisons
Adopt cardinal rankings
Allow interpersonal cardinal utilitiesIsaac Levi in Hard Choices provides an account of rational decision making under unresolved conflict
Conflicts which occur when individual values cannot agree on a course of action
Reject pair-wise comparisons
Adopt cardinal rankings
Allow interpersonal cardinal utilities
32. Understanding the President Two of his key values are in conflict over the issue of how to rebuild Iraq
Fiscal Conservative – Expenses for the US
Hawk – Expansion of US control
33. Understanding the President Examining how his values rank the options:
Expenses:
UN Led: $150 Million
NATO Led: $405 Million
USA Led: $1 Billion
Control:
USA Led: 100% Effective
NATO Led: 77.5% Effective
UN Led: 25% Effective
34. Understanding the President We set each value as an axis, and place each option on these depending on their relative desirability
35. Understanding the President We then take the weighted average of each option over these values
36. Understanding the President Those options which form the dominating upper bound over these values are then admissible under these values
37. Understanding the President Second-order values can then break any ties created by the first order values Note this is a lexicographic ordering…Note this is a lexicographic ordering…
38. Understanding the President Second-order values can then break any ties created by the first order values Note this is a lexicographic ordering…Note this is a lexicographic ordering…
39. Understanding the President When the NATO option is no longer available, the option of setting up a Puppet Regime is under consideration
40. Understanding the President Examining how his values order the options:
Expenses:
UN Led: $150 Million
Puppet Regime: $745 Million
USA Led: $1 Billion
Control:
USA Led: 100% Effective
Puppet Regime: 47.5%Effective
UN Led: 25% Effective
41. Understanding the President The Puppet Regime option is NOT admissible under these values…
42. Understanding the President So USA option is preferred
43. Second Best and Second Worst Options Distinguish between second-best and second-worst: This is not possible with purely ordinal rankings… remember, both NATO and Puppet occupy the same place in the orderings relative to the other optionsThis is not possible with purely ordinal rankings… remember, both NATO and Puppet occupy the same place in the orderings relative to the other options
44. Understanding Cycles Pair-wise comparisons yield a cycle
Favors UN over NATO
Favors NATO over Puppet Regime
Yet, favors a Puppet Regime over the UN
When faced with all three options, chooses UN
45. Understanding Cycles When faced with all three options…
46. Understanding Cycles When faced with all three options…
47. Understanding Cycles UN vs. NATO – UN wins
48. Understanding Cycles UN vs. NATO – UN wins
49. Understanding Cycles NATO vs. Puppet Regime - NATO wins
50. Understanding Cycles Yet, Puppet Regime vs. UN – Puppet Regime Wins
51. Understanding Cycles Yet, Puppet Regime vs. UN – Puppet Regime Wins
52. Alternative Foundation for “Rational” Choice Making Devalue pair-wise comparisons
Use cardinal rankings with a lexicographic method
Allows to
Distinguish between second-best and second-worst
Rationalize some cycles Pair-wise comparisons are no longer important
Use cardinal rankings over the relevant values and have a lexicographic method for determining admissible options
Can distinguish between second-best and second-worst options
Cycles can have a rational explanationPair-wise comparisons are no longer important
Use cardinal rankings over the relevant values and have a lexicographic method for determining admissible options
Can distinguish between second-best and second-worst options
Cycles can have a rational explanation
53. Social Choice Making Each individual has cardinal ranking(s)… Gets complicated when individual is using multiple values which are conflicted (then each individual has a range of cardinal values for each option)Gets complicated when individual is using multiple values which are conflicted (then each individual has a range of cardinal values for each option)
54. Social Choice Making … which are interpersonally comparable… The actual weights must be some positive affine transformation of the values of the individual…The actual weights must be some positive affine transformation of the values of the individual…
55. Social Choice Making … and begin to eliminate options
Many ways to do this!! There are many ways to eliminate options… can use expected value, maximin, etc… perhaps some lexical combinationThere are many ways to eliminate options… can use expected value, maximin, etc… perhaps some lexical combination
56. The Role for Deliberation Reveals the dimensions to the issue
Allows participants to communicate effectively with one another
Supplies cardinal values to their preferences
Makes possible for determining interpersonally comparable interests
Allows participants to become aware of trade-offs between aggregation mechanisms involving interpersonal comparisons
Facilitate agreement on a procedure for combining interpersonally comparable interests into a social choice Deliberation can reveal the dimensions to the issue
Reveals what values are in conflict
Identifies first-order values, second-order values, etc…
Deliberation allows participants to communicate with one another
Through descriptive language, narratives, good rhetoric, scientific studies, … participants can supply cardinal values to their preferences
This leads to the possibility for determining those interests which are interpersonal comparable
Deliberation can reveal the dimensions to the issue
Reveals what values are in conflict
Identifies first-order values, second-order values, etc…
Deliberation allows participants to communicate with one another
Through descriptive language, narratives, good rhetoric, scientific studies, … participants can supply cardinal values to their preferences
This leads to the possibility for determining those interests which are interpersonal comparable
57. Conclusions Pair-wise comparisons screen off valuable information
Prevents us from seeing certain admissible and inadmissible options (second best and second worst options)
Cannot comprehend how some cycles might be rational
With pair-wise comparisons we can never know if participants’ preferences have a richer, more subtle structure
58. Conclusions Deliberative democrats have to go further if they wish to respond to their social choice critics
They only challenge the surface assumptions in social choice
There are alternative ways to defend deliberative democracy from its social choice critics
Challenge deeper assumptions in social choice theory