This is a question to ask the social engineers employed by those who own SE and SO, but I would like to vet it here before doing that.
Background
Consider that the SE/SO structure is, from one perspective, a game, whether or not it was intended to be. In the context of the best of the social networking models that have obtained some success on today's web, all of which were derived from or influenced by Morgenstern and von Neuman's Game Theory, gaming the system is what contributors to the content of the site do.
From a systems analysis perspective, whether their intention is any of the following or some proportional combination of them, playing for some objective can be proven as the prime motivator for all SE engagement.
- Obtaining an answer for use in a project or to satisfy an interest
- Educating one's self by writing and evaluating responses
- Educating others out of purpose driven or altruistic motivation
- Gaining reputation to be seen in a community as an expert
- Writing because of satisfaction in writing
- Interest in public affirmation of intelligence or expertise
- Intrinsic value of high numeric reputation resulting from good PR
- Addictive compulsion lacking a cognitive cause
- Some other reason
The SE/SO system has adapted for the purposes of growth, and it works as is. The original domain stackoverflow.com is rated 64th globally by Alexa, and the AI beta's main domain stackexchange.com is rated 127th.
In this context, the deltas aggregated in member reputation incentivizes behaviors that cause the increased growth of SE and SO through the system.
How This Social Model Applies to Down Voting
There are two distinct types of down votes.
- Anonymous down vote
- Down vote with associated reasoning for it
Both have purpose in that the identify a perceived error or inappropriateness of the Q or A. Both currently have the same negative affect on the voter's reputation.
Is this optimal?
Critique from a Social Network Equilibrium Perspective
The advantage of the SE/SO system's game objective to humanity is that it helps the global development and dissemination of subject specific knowledge. From a house (SE/SO business) perspective, it is to improve the domain's rating globally.
With regard to both of those game objectives, a down vote with an associated reason has greater value than an anonymous one in two respects.
- Anonymity decouples the down vote from an ethical incentive.
- The expression of reasons provides additional information to both writer and the entire public readership.
The current SE system merely indicates to the down voter that a reason in the comments is preferred. It makes much more sense from an optimization point of view to use the reputation system to simultaneously.
- Incentivize against down voting with ulterior motives.
- Incentivize for information transparency.
The first is part of civilization in that those indicted can face their critic in academia and face their accuser in court. The legal ethics behind this has much to do with the necessary checks and balances in civilized social structure. The asymmetry of accountability in being able to dispute an answer and not being required to specify why leads to uncivilized behavior, which is why academia and ethically evolved legal systems do not permit it.
Potentially Beneficial Change
The overall metrics of satisfaction, positive impact on global understanding, and the value of the two domains (SO and SE) would likely be improved if transparency was not sacrificed for the sake of anonymity.
This is a potentially beneficial change.
Anonymous down votes would still be permitted but a higher integer value would be subtracted from the voter's reputation than 1.
Reason associated down votes would not subtract anything from the voter's reputation, since the action has as much a reason to incentivize as a reason to incentivize against.
A Possible Implementation
To implement such, in addition to the verbal encouragement of adding a comment when a down vote is cast, the comment field labeled, "Reason for down vote," could be added with a minimum required number of words, the provision of which differentiates the two cases so that reputation adjustment could reflect the more optimal incentive model regarding down voting.
Transparency With Anonymity
Down voting transparency and anonymity could easily be achieved concurrently by creating an Anonymous user for such purposes. This solves the problem of retaliatory conduct, but it may not solve the problem of asymmetric accountability, where one can harm another without any risk of consequences, which is a policy not found in well developed systems outside the SE/SO space.
The question then becomes, why did academia and ethical judicial systems require transparency without anonymity except when a child or undercover public servant is involved?