While offering simplicity, ease of use, low error count, transparency and easy adaptivity D21 - Janeček method can remediate problems which can be attributed to the limitations of the current voting rules: rising political polarization, low voter turnout, and political disengagement.
The D21 - Janeček method addresses shortcomings of the earlier proposed voting methods by introducing a news dimension: systematically capped multiple votes, which enable voters to express their preferences reflecting multidimensional issue space. It permits voters to cast multiple votes that are either plus or minus. The upper boundary of the total number of votes is pegged to the number of ballot options and the number of plus voted cast by each voter must be at least twice the number of minus votes cast. Hence it can fluctuate base on the number of choices and a degree of desired consensus to be achieved.
By allowing voters to cast in a single ballot more than one vote, it incentivizes civic engagement by bringing voters closer to achieving maximum utility whilst reflecting voters´ preferences and rewarding consensual candidates.
An option of casting multiple votes will impel the electorate to carefully consider and weigh their choices and deliberate with one another. It will also motivate candidates to converge to the political center, away from a polarized ideological spectrum, for maximization of the probability of winning by changing their positions, something propelled by the possibility of shared votes and in response to changes in beliefs about electorate preferences. Under D21 - Janeček method candidates with broader appeal are less likely to attack one another to their mutual detriment. On the contrary, they might partially support each other in pre-election campaigning in order to attract the second votes of the primary voters of the opponent.
How did the whole the whole thing start?
Surveys and analyses
Karel Janeček: D21 method (PDF)