Equality by lot

Matthew Gray is a Mathematician, Software Engineer, and Theoretical Computer Scientist currently teaching at Renton Technical College after working at Microsoft Norway. His primary research interests are in Secure Multiparty Computation, Quantum Cryptography, and Coding Theory. Over the last year he has been researching how sortition can be conducted in secure and trustworthy ways.

Judging from the aftermath of contested elections around the world, if large numbers of people question the fairness of a sortition selection there could be dire consequences. Our current systems for generating the randomness needed for selections are not secure enough to silence those questions, especially when used to select national representatives. The current systems are all centralized and non-participatory, some are vulnerable to local cheating, and all are vulnerable to sabotage from well-resourced malicious actors, such as state security services. This article proposes a new option. It lays out a specific decentralized and participatory method of selecting representatives by explains how two people can go about fairly choosing one of them to be selected and then showing how the method can be scaled up for larger selections. It also touches on some of the mathematics surrounding these methods.

Current systems for generating the randomness needed for drawings fall into two main categories. First are physical systems such as dice, floating balls, or names in hats. These work better in small communities where every member can show up and observe. But even in those spaces, if people distrust their neighbors, they will worry about the dice being weighted or someone sneaking extra copies of their name into the hat. Second are digital systems that take some outside sources of randomness and process them to get some final randomness. These outside sources of randomness include stock market indexes, lava lamps, or cameras whose lenses have been painted over. 

Digital systems tend to involve math that is fairly complicated, don’t feel that random, and aren’t interesting to look at. Also, because of the complicated math involved, there’s a chance that these processes aren’t actually random after all. Neither category produces systems that involve citizens or are particularly resilient to sabotage efforts. Weighting dice or hacking a computer is easy. Manipulating the stock market is hard but may not be beyond the abilities of a state security service. However if we include everyone in the process of generating the randomness we can create systems that have no single point of failure.

To introduce the ideas used by the system I am about to propose, let’s imagine that the team captains (Luka and Hugo) in the last FIFA World Cup didn’t trust the coin that was going to be used at the start of the match. One way they could generate the “coin flip” together is for both captains to bring their own coins and flip them simultaneously. If both coins land on the same side (i.e. both heads or both tails) then France wins the coin toss, if they land on different sides (i.e. heads tails or tails heads) then Croatia wins. What is important to note here is that even if one coin is weighted, as long as the other one is unweighted, then the overall “coin flip” is fair. 

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Filed under: Participation, Proposals, Sortition | Tagged: randomization | 26 Comments »

Worries are sometimes expressed about the impossibility of generating a sample of people at random in a way that cannot be manipulated by powerful actors. Sources of physical data are either too predictable to be of use or require machinery that is too arcane or sensitive to be effectively publicly verifiable. Social sources of data – such as the stock market or blockchain transactions – may be influenced powerful forces in society. Many randomizations that rely on explicit and symmetrical inputs from the public as a source of randomness have to utilize aggregation procedures that may allow those with advance knowledge of others’ inputs to manipulate the outcomes. With the prevailing mood of generalized distrust in institutions, a randomization mechanism would have to be completely open and verifiable to have a reasonable chance of inspiring confidence.

My proposal for such a mechanism is a simple elimination procedure which works as follows. At the outset, one candidate is eliminated. This candidate then gets to eliminate another, who then gets to eliminate another, and so on. The selection thus proceeds by sequential elimination of candidates until only one, or however many appointees are desired, remain.

This procedure is easily verifiable by any observer since it is self-contained and does not involve secrets, fancy machinery or fancy calculations. All the decisions involved are made in the open and cannot be foreseen in advance.

In addition to being manipulation resistant, this procedure has the advantage that it involves all interested citizens in the selection procedure and allows them to influence the outcome. By creating a new form of mass political participation, this procedure addresses the oft-heard objection to sortition that it deprives people from having influence over the appointment of decision makers.

In fact, while, like any form of mass participation, the impact made by any single decision-maker is minute, this form of participation is more meaningful than electoral participation because the choice made by each person – who to eliminate – is entirely unrestricted. This is in contrast which the electoral choice which is restricted a-priori by a primaries process in which the field of candidates is drastically narrowed-down. In the proposed procedure, citizens are completely free to make their elimination choices as they see fit, even if it may be seen as a sign of good citizenship to make this choice at random.

A minor technical point: The first candidate to be eliminated, the starting point of the elimination chain, can be chosen arbitrarily – this is not a position of decisive power, but rather the opposite, a position of disadvantage. If no other procedure is found suitable, an election can be used to select this person.

Filed under: Participation, Proposals, Sortition | Tagged: randomization | 18 Comments »