Why is it important to encourage people to vote?

The basic formula for determining whether someone will vote is PB + D > C. Here, P is the probability that an individual's vote will affect the outcome of an election, and B is the perceived benefit of that person's favoured political party or candidate being elected. D originally stood for democracy or civic duty, but today represents any social or personal gratification an individual gets from voting. C is the time, effort, and financial cost involved in voting. Since P is virtually zero in most elections, PB is also near zero, and D is thus the most important element in motivating people to vote. For a person to vote, these factors must outweigh C.