Kai Spiekermann

Kai Spiekermann

Professor of Political Philosophy
London School of Economics

Posts by Collection

portfolio

publications

Liberalismus und Rechtsstaat: Thesen zu EMRK und europäischer Identität

Published in 30 Jahre EMRK-Beitritt der Schweiz: Erfahrungen und Perspektiven, 2005

Recommended citation: Good, Paul-Lukas and Spiekermann, Kai (2005) "Liberalismus und Rechtsstaat: Thesen zu EMRK und europäischer Identität", in 30 Jahre EMRK-Beitritt der Schweiz: Erfahrungen und Perspektiven, pp. 19–42.

Translucency, Assortation, and Information Pooling: How Groups Solve Social Dilemmas

Published in Politics, Philosophy & Economics, 2007

In one-shot public goods dilemmas, defection is the strictly dominant strategy. However, agents with cooperative strategies can do well if agents are “translucent” (that is, if agents can fallibly recognize the strategy other agents play ex ante) and an institutional structure allows “assortation” such that cooperative agents can increase the likelihood of playing with their own kind. The model developed in this article shows that even weak levels of translucency suffice if cooperators are able to pool their information to exclude defectors.

Recommended citation: Spiekermann, Kai (2007) "Translucency, Assortation, and Information Pooling: How Groups Solve Social Dilemmas", Politics, Philosophy & Economics, 6(3), pp. 303–324.
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Reply: Clubbish Justice

Published in Politics, Philosophy & Economics, 2008

Replying to my earlier article “Translucency, Assortation, and Information Pooling: How Groups Solve Social Dilemmas”, Robert Goodin examines the normative implications of the rule “cooperate with those whose inclusion benefits the larger scheme of cooperation”, and gives several reasons for why the conversion of justice into a club good is normatively unappealing. This reply to Goodin discusses whether the rule leads to an exclusion of poor agents, whether a group should hire agents to detect free-riders, and how a group should deal with naive cooperators. The rule can be defended as an enforcement mechanism in some cases, but it is normatively unappealing as a theory of justice.

Recommended citation: Spiekermann, Kai (2008) "Reply: Clubbish Justice", Politics, Philosophy & Economics, 7(4), pp. 447–453.
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Published in , 1900

Judgement Aggregation and Distributed Thinking

Published in AI and Society, 2010

In recent years, judgement aggregation has emerged as an important area of social choice theory. Judgement aggregation is concerned with aggregating sets of individual judgements over logically connected propositions into a set of collective judgements. It has been shown that even seemingly weak conditions on the aggregation function make it impossible to find functions that produce rational collective judgements from all possible rational individual judgements. This implies that the step from individual judgements to collective judgements requires trade-offs between different desiderata, such as universal domain, rationality, epistemological quality, and unbiasedness.

Recommended citation: Spiekermann, Kai (2010) "Judgement Aggregation and Distributed Thinking", AI and Society, 25(4), pp. 401–412.
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Rules, Norms, and Commitment

Published in Handbook of Philosophy of Social Sciences, 2011

This handbook provides a wide-ranging and authoritative overview of the main philosophical currents and traditions at work in the social sciences today. It explores fundamental issues like ontology, epistemology, methodology, and key concepts such as paradigm, empiricism, agency, power, and causality. The chapter on Rules, Norms, and Commitment examines what is the relationship between the social sciences and the natural sciences and where today’s dominant approaches to doing social science come from.

Recommended citation: Peter, Fabienne and Spiekermann, Kai (2011) "Rules, Norms, and Commitment", in Handbook of Philosophy of Social Sciences, pp. 216–232.
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Courts of many minds

Published in British Journal of Political Science, 2012

In A Constitution of Many Minds Cass Sunstein argues that the three major approaches to constitutional interpretation - Traditionalism, Populism and Cosmopolitanism - all rely on some variation of a ...

Recommended citation: Spiekermann, K. and Goodin, R.E. (2012) "Courts of many minds", British Journal of Political Science, 42(3), pp. 555–571.
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Epistemic Aspects of Representative Government

Published in European Political Science Review, 2012

The Federalist, justifying the Electoral College to elect the president, claimed that a small group of more informed individuals would make a better decision than the general mass. But the Condorcet Jury Theorem tells us that the more independent, better-than-random voters there are, the more likely it will be that the majority among them will be correct. The question thus arises as to how much better, on average, members of the smaller group would have to be to compensate for the epistemic costs of making decisions on that many fewer votes. This question is explored in the contexts of referendum democracy, delegate-style representative democracy, and trustee-style representative democracy.

Recommended citation: Goodin, Robert E and Spiekermann, Kai (2012) "Epistemic Aspects of Representative Government", European Political Science Review, 4(3), pp. 303–325.
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Epistemic Democracy with Defensible Premises

Published in Economics and Philosophy, 2013

The contemporary theory of epistemic democracy often draws on the Condorcet Jury Theorem to formally justify the “wisdom of crowds”. But this theorem is inapplicable in its current form, since one of its premises – voter independence – is notoriously violated. This premise carries responsibility for the theorem’s misleading conclusion that “large crowds are infallible”. We prove a more useful jury theorem: under defensible premises, “large crowds are fallible but better than small groups”. This theorem rehabilitates the importance of deliberation and education, which appear inessential in the classical jury framework.

Recommended citation: Dietrich, Franz and Spiekermann, Kai (2013) "Epistemic Democracy with Defensible Premises", Economics and Philosophy, 29(1), pp. 87–120.
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Independent Opinions? On the Causal Foundations of Belief Formation and Jury Theorems

Published in Mind, 2013

This paper addresses the claim that opinions are more likely to be correct if they are held independently by many individuals, often used as an argument in social epistemology to defend democratic decision-making on grounds of the wisdom of crowds. The authors distinguish four probabilistic notions of opinion independence and identify causal conditions guaranteeing each kind.

Recommended citation: Dietrich, Franz and Spiekermann, Kai (2013) "Independent Opinions? On the Causal Foundations of Belief Formation and Jury Theorems", Mind, 122(487), pp. 655-685.
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Buying Low, Flying High: Carbon Offsets and Partial Compliance

Published in Political Studies, 2014

Many companies offer their customers voluntary carbon “offset” certificates to compensate for greenhouse gas emissions. Voluntary offset certificates are cheap because the demand for them is low, allowing consumers to compensate for their emissions without significant sacrifices. Regarding the distribution of emission reduction responsibilities I argue that excess emissions are permissible if they are offset properly. However, if individuals buy offsets only because they are cheap, they fail to be robustly motivated to choose a permissible course of action.

Recommended citation: Spiekermann, Kai (2014) "Buying Low, Flying High: Carbon Offsets and Partial Compliance", Political Studies, 62(4), pp. 913–929.
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Small Impacts and Imperceptible Effects: Causing Harm with Others

Published in Midwest Studies in Philosophy, 2014

The problem of imperceptible effects arises because very small changes are not perceived, even if many of these small changes together are. If the normatively relevant consequences of an action, holding all other actions fixed, cannot be perceived, we are challenged to explain what makes the action wrong. I argue that an action can be wrong because it can cause an effect together with other actions.

Recommended citation: Spiekermann, Kai (2014) "Small Impacts and Imperceptible Effects: Causing Harm with Others", Midwest Studies in Philosophy, 38(1), pp. 75–90.
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Epistemic Solidarity as a Political Strategy

Published in Episteme, 2015

Solidarity is supposed to facilitate collective action. We argue that it can also help overcome false consciousness. Groups practice epistemic solidarity if they pool information about what is in their true interest and how to vote accordingly. The more numerous Masses can in this way overcome the Elites, but only if they are minimally confident with whom they share the same interests.

Recommended citation: Goodin, Robert E and Spiekermann, Kai (2015) "Epistemic Solidarity as a Political Strategy", Episteme, 12(4), pp. 439–457.
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Published in , 1900

Published in , 1900

An Epistemic Theory of Democracy

Published in Oxford University Press, 2018

This book examines the Condorcet Jury Theorem and how its assumptions can be applicable to the real world. It will use the theorem to assess various familiar political practices and alternative institutional arrangements, revealing how best to take advantage of the truth-tracking potential of majoritarian democracy.

Recommended citation: Goodin, Robert E. and Spiekermann, Kai (2018) An Epistemic Theory of Democracy, Oxford: Oxford University Press.
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Directed Reflective Equilibrium: Thought Experiments and How to Use Them

Published in Journal of Moral Philosophy, 2020

Abstract In this paper we develop a new methodology for normative theorising, which we call Directed Reflective Equilibrium. Directed Reflective Equilibrium is based on a taxonomy that distinguishes b…

Recommended citation: Slavny, Adam and Spiekermann, Kai and Lawford-Smith, Holly and Axelsen, David V. (2020) "Directed Reflective Equilibrium: Thought Experiments and How to Use Them", Journal of Moral Philosophy, 18(1), pp. 1-25.
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Epistemic Network Injustice

Published in Politics, Philosophy and Economics, 2020

Epistemic Network Injustice arises when a subset of citizens is systematically deprived of connections to helpful epistemic peers, leading to their reduced political influence. This paper examines how to identify epistemic peers in a stylized political setting of electoral competition between Masses and Elites.

Recommended citation: Spiekermann, Kai (2020) "Epistemic Network Injustice", Politics, Philosophy and Economics, 19(1), pp. 83-101.
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Jury Theorems

Published in The Routledge Handbook of Social Epistemology, 2020

Recommended citation: Dietrich, Franz and Spiekermann, Kai (2020) "Jury Theorems", in The Routledge Handbook of Social Epistemology.
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Why Populists Do Well on Social Media

Published in Global Justice : Theory Practice Rhetoric, 2020

A link between populism and social media is often suspected. This paper spells out a set of possible mechanisms underpinning this link: that social media changes the communication structure of the pub…

Recommended citation: Spiekermann, Kai (2020) "Why Populists Do Well on Social Media", Global Justice : Theory Practice Rhetoric, 12(02), pp. 50-71.
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Jury Theorems

Published in The Stanford Encyclopedia of Philosophy, 2021

Jury theorems are mathematical theorems about the ability ofcollectives to make correct decisions. Several jury theorems carry the optimistic message that, in suitable circumstances, “crowds arewise”: …

Recommended citation: Dietrich, Franz and Spiekermann, Kai (2021) "Jury Theorems", The Stanford Encyclopedia of Philosophy.
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Published in , 1900

Good reasons for losers: lottery justification and social risk

Published in Economics & Philosophy, 2022

Many goods are distributed by processes that involve randomness. In lotteries, randomness is used to promote fairness. When taking social risks, randomness is a feature of the process. The losers of such decisions ought to be given a reason why they should accept the outcome. Surprisingly, good reasons demand more than merely equal ex ante chances.

Recommended citation: Spiekermann, Kai (2022) "Good reasons for losers: lottery justification and social risk", Economics & Philosophy, 38(1), pp. 108-131.
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Does Diversity Trump Ability?

Published in Politische Vierteljahresschrift, 2024

A roundtable discussion on the diversity trumps ability (DTA) theorem by economists Lu Hong and Scott E. Page. Examines whether cognitively more diverse groups are better at solving problems than less diverse groups, with debate on the combining of diverse heuristics in cooperative search processes and whether deliberation is always beneficial.

Recommended citation: Niesen, Peter and Spiekermann, Kai and Herzog, Lisa and Girard, Charles and Vogelmann, Frieder (2024) "Does Diversity Trump Ability?", Politische Vierteljahresschrift, 65(4), pp. 785-805.
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Deliberation and the wisdom of crowds

Published in Economic Theory, 2025

Does pre-voting group deliberation improve majority outcomes? To address this question, we develop a probabilistic model of opinion formation and deliberation. Two new jury theorems, one pre-deliberation and one post-deliberation, suggest that deliberation is beneficial. Successful deliberation mitigates three voting failures: overcounting widespread evidence, neglecting evidential inequality, and neglecting evidential complementarity.

Recommended citation: Dietrich, Franz and Spiekermann, Kai (2025) "Deliberation and the wisdom of crowds", Economic Theory, 79(2), pp. 603-655.
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Irreversible Loss

Published in The Oxford Handbook of Intergenerational Ethics, 2025

The philosopher John Rawls once said that “the question of justice between generations…subjects any ethical theory to severe if not impossible tests.” This volume aims to illuminate those tests, ind…

Recommended citation: Spiekermann, Kai (2025) "Irreversible Loss", in The Oxford Handbook of Intergenerational Ethics, pp. 416-431.
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What Are Social Norms?

Published in Unpublished manuscript, 2025

Most recent theorists take social norms to arise from certain attitudes, such as expectations on others, perhaps along with conforming practices. Challenging this view, we argue that social norms are instead grounded in a social norming process: an (often non-verbal) social communication process that institutes or ‘makes’ the norm. We present different versions of a process-based account of social norms and social normativity. The process-based view brings social norms closer to legal norms, by taking social norms to arise through ‘expressive acts’, just as some laws and contracts arise through acts of voting or signing, not through mere attitudes.

Recommended citation: Dietrich, Franz and Spiekermann, Kai (2025) "What Are Social Norms?", Unpublished manuscript.
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Generative Democracy: New Foundations for Democratic Theory

Published in Book manuscript in preparation, 2026

This book examines the Condorcet Jury Theorem and how its assumptions can be applicable to the real world. It will use the theorem to assess various familiar political practices and alternative institutional arrangements, revealing how best to take advantage of the truth-tracking potential of majoritarian democracy.

Recommended citation: Dietrich, Frand and Spiekermann, Kai (in development, likely publication 2026) Generative Democracy: New Foundations for Democratic Theory

talks

teaching

Teaching experience 1

Undergraduate course, University 1, Department, 2014

This is a description of a teaching experience. You can use markdown like any other post.

Teaching experience 2

Workshop, University 1, Department, 2015

This is a description of a teaching experience. You can use markdown like any other post.