Information complexity of strategic voting
|Author:||Mgr. Palguta Ján|
|Year:||2011 - summer|
|Leaders:|| † prof. RNDr. Ing. František Turnovec CSc.
|Work type:|| Doctoral
|Awards and prizes:|
|Abstract:||This thesis in political economy considers the concept of strategic optimisation of
voting behaviour under imperfect information. Under strategic voting we understand
an act of voting for other than voter’s best preferred (order of) alternatives.
Motivation for this thesis comes from the empirically witnessed fact that a substantial
portion of the electorate votes for their second or third best preferred alternatives,
seeing that their most preferred alternatives face in expectation low probabilities of
voting success. At other instances, the voters vote strategically with the intentions of
strengthening the coalitional partners to their best choices or to weaken the coalitional
partners of the undesired parties. Despite to the evident individual rationality of the
strategic voting, strategic voting is typically socially suboptimal. Strategic voting
leads to social choices that do not reflect the truthful preferences of the public.
Via a series of computation-based simulations the thesis studies the relative
vulnerability of the most common voting procedures to strategic manipulation. The
thesis categorizes these voting procedures by their degree of susceptibility to voting
manipulation. By standard econometric techniques it confirms that strategic voting is
most threatening in small groups, typically in committees, boards of directors, or in
other small collective decision-making bodies. The thesis then relaxes the assumption
of complete information, which is central for the Gibbard-Satterthwaite‘s
impossibility theorem to predict strategic voting. We confirm that in small decisionmaking
bodies even a small reduction in the amount of possessed information can
severely threaten the agent’s ability to strategically manipulate the vote. For some
procedures such reduction in information precludes strategic voting. This finding
applies both for an absolute and relative drop in the amount of possessed information.
On the other hand, if a committee member knows exactly the voting patterns of her
colleagues, the probability of strategic manipulation rises substantially.
|Downloadable:|| Rigorous Thesis Palguta