A condition suffered by a person or persons that strive towards a given goal but with absolutely no idea how their actions or planned actions will actually achieve the desired result.
Phrase derived from the underpants gnomes
characters from the TV series 'South Park' that collected and stockpiled used underpants for the purpose of making a profit but had no idea of how to actually achieve this.
Demonstrators protesting against nuclear power but not considering how they will pay the ever increasing cost of power derived from the diminishing fossil fuel supply suffer a severe case of Underpants Gnome Syndrome.
Ex UK Prime Minister Gordon Brown suffered a major case of Underpants Gnome Syndrome when he thought that reducing VAT (sales Tax) by 2.5% last year would significantly stimulate consumer spending.