Surprising (and confusing!) as it may be, there is some evidence that voters would vote differently with their Demeny vote than with their first vote.
I’ve asked Ben Grodeck (who clued me into Demeny voting) to weigh in with more data, but for now see this study from Japanese economist Reiko Aoki, who found (Table 8 and Figure 7) that the voting preferences of surveyed participants who are permitted to cast one vote on behalf of themselves and one vote for their child sometimes vote differently on their second vote. The effect isn’t drastic, but it is certainly non-trivial.
The study authors further find that policy preferences on behalf of oneself and on behalf of one’s children diverge to a greater degree, and the authors hypothesize that we would see more divergence between the multiple votes of Demeny voters if they had different political options that better reflected the divergence between these sets of preferences. Thus, they think that instituting Demeny voting would cause party platforms to change to try to cater to the policy preferences of parents voting on behalf of their children.
I had the same intuition as RhysSouthan that most people who acquire the second vote in a Demeny voting structure would use the two votes for the same party/candidate/policy . I think an important facet here is that the salience of the vote being for the ‘future generation’ may nudge people on the margin to use both votes for the policy/party that best benefits the future generation, whereas without receiving the second vote they may not have voted this way. The Kochi University of Technology Research Institute of Future Design have some papers that show making future generations salient increases pro-social behaviour towards future generations. Thus, I think this the above hypothesis is plausible. Also, as Tyler showed above, even marginal changes of the second vote (from the first) that benefits future generations would be a good thing. I do think motivated reasoning is a big concern here though ( people manipulating their beliefs to think that their vote is good for future generations, when in fact it is not), and it would be interesting to see if there is any evidence of this.
The same institute actually just published a paper using a lab experiment to investigate the psychological effects of Demeny Voting. (I need to re-read the paper, as it has changed from their working paper version, which I read recently). However, the paper investigates the voting behaviour of people who do not receive the second vote (single-ballot voters). They hypothesise that these single-ballot voters may be more likely to use their vote for the benefit of future generations in a Demony Voting structure due to either:
a) The cost of behaving ethically decreases as their vote has less impact on the overall outcome. However, they do not find any evidence of this in their data (NPV Treatment: Demony voting, but participants are not told why a second vote was allocated to some people). The authors argue that single ballot voters may perceive the voting structure to be unfair, inducing them to vote more egotistically in this treatment.
b) A bandwagon effect (conformity): These voters expect that more votes will be used on the policy that benefits future generations, as a result of others getting a second vote (and told to use it for the interest of future generations) “promoting the ethical voting of single ballot voters.”
They find evidence supporting the bandwagon effect. When people are told why a second vote is given in a Demony Voting structure (PV treatment), single ballot voters are more likely to vote for the policy that benefits the future compared to the NPV treatment. (Note: I am not sure a bandwagon effect is the best model to explain this result).
The authors contend that “these results suggest that the success of the new voting scheme suggested by Demeny should depend on whether the rationale behind giving some voters a second ballot is explained and understood.”
It is important to highlight that this is a single lab experiment, and external validity concerns are legitimate (to the authors credit they make sure to talk about this at the end of the paper). Field experiments, the use of observational data, and further lab experiments are all necessary to get a better understanding of how Demony Voting affects voter’s behaviour, but it’s exciting to see academics interested in what I believe is an important question.
One concern with that system that came to my mind is the possibility that explicitly assigning one vote for a person’s own use and one for a person’s use on behalf of future generations could make the idea of voting in a more self-interested/short-termist way more salient, as well as making it seem more acceptable, or even like it’s the norm that they’re being encouraged to follow. It seems like it might therefore make people more likely to use “their own” vote in a more self-interested/short-termist way (which could just cancel out the increased longtermism of people’s “second votes”, rather than making things worse overall).
But that’s entirely speculative, and seems to me somewhat less likely than Demeny Voting causing people to (a) just vote twice for what they would’ve voted for anyway, (b) use “their own” vote like they would’ve anyway but their “second” vote in more longtermist way, or (c) use both votes in a more longtermist way. But it still seems like that’s a concern worth investigating. (It’s possible it’s been investigated already—I haven’t read any of the linked papers.)
Surprising (and confusing!) as it may be, there is some evidence that voters would vote differently with their Demeny vote than with their first vote.
I’ve asked Ben Grodeck (who clued me into Demeny voting) to weigh in with more data, but for now see this study from Japanese economist Reiko Aoki, who found (Table 8 and Figure 7) that the voting preferences of surveyed participants who are permitted to cast one vote on behalf of themselves and one vote for their child sometimes vote differently on their second vote. The effect isn’t drastic, but it is certainly non-trivial.
http://hermes-ir.lib.hit-u.ac.jp/rs/bitstream/10086/22250/1/cis_dp539.pdf
The study authors further find that policy preferences on behalf of oneself and on behalf of one’s children diverge to a greater degree, and the authors hypothesize that we would see more divergence between the multiple votes of Demeny voters if they had different political options that better reflected the divergence between these sets of preferences. Thus, they think that instituting Demeny voting would cause party platforms to change to try to cater to the policy preferences of parents voting on behalf of their children.
I had the same intuition as RhysSouthan that most people who acquire the second vote in a Demeny voting structure would use the two votes for the same party/candidate/policy . I think an important facet here is that the salience of the vote being for the ‘future generation’ may nudge people on the margin to use both votes for the policy/party that best benefits the future generation, whereas without receiving the second vote they may not have voted this way. The Kochi University of Technology Research Institute of Future Design have some papers that show making future generations salient increases pro-social behaviour towards future generations. Thus, I think this the above hypothesis is plausible. Also, as Tyler showed above, even marginal changes of the second vote (from the first) that benefits future generations would be a good thing. I do think motivated reasoning is a big concern here though ( people manipulating their beliefs to think that their vote is good for future generations, when in fact it is not), and it would be interesting to see if there is any evidence of this.
The same institute actually just published a paper using a lab experiment to investigate the psychological effects of Demeny Voting. (I need to re-read the paper, as it has changed from their working paper version, which I read recently). However, the paper investigates the voting behaviour of people who do not receive the second vote (single-ballot voters). They hypothesise that these single-ballot voters may be more likely to use their vote for the benefit of future generations in a Demony Voting structure due to either:
a) The cost of behaving ethically decreases as their vote has less impact on the overall outcome. However, they do not find any evidence of this in their data (NPV Treatment: Demony voting, but participants are not told why a second vote was allocated to some people). The authors argue that single ballot voters may perceive the voting structure to be unfair, inducing them to vote more egotistically in this treatment.
b) A bandwagon effect (conformity): These voters expect that more votes will be used on the policy that benefits future generations, as a result of others getting a second vote (and told to use it for the interest of future generations) “promoting the ethical voting of single ballot voters.”
They find evidence supporting the bandwagon effect. When people are told why a second vote is given in a Demony Voting structure (PV treatment), single ballot voters are more likely to vote for the policy that benefits the future compared to the NPV treatment. (Note: I am not sure a bandwagon effect is the best model to explain this result).
The authors contend that “these results suggest that the success of the new voting scheme suggested by Demeny should depend on whether the rationale behind giving some voters a second ballot is explained and understood.”
It is important to highlight that this is a single lab experiment, and external validity concerns are legitimate (to the authors credit they make sure to talk about this at the end of the paper). Field experiments, the use of observational data, and further lab experiments are all necessary to get a better understanding of how Demony Voting affects voter’s behaviour, but it’s exciting to see academics interested in what I believe is an important question.
One concern with that system that came to my mind is the possibility that explicitly assigning one vote for a person’s own use and one for a person’s use on behalf of future generations could make the idea of voting in a more self-interested/short-termist way more salient, as well as making it seem more acceptable, or even like it’s the norm that they’re being encouraged to follow. It seems like it might therefore make people more likely to use “their own” vote in a more self-interested/short-termist way (which could just cancel out the increased longtermism of people’s “second votes”, rather than making things worse overall).
But that’s entirely speculative, and seems to me somewhat less likely than Demeny Voting causing people to (a) just vote twice for what they would’ve voted for anyway, (b) use “their own” vote like they would’ve anyway but their “second” vote in more longtermist way, or (c) use both votes in a more longtermist way. But it still seems like that’s a concern worth investigating. (It’s possible it’s been investigated already—I haven’t read any of the linked papers.)