Did you know that a Belgian holds the key to the elections?


More than 100 years ago, Victor D'Hondt developed a mathematical formula, still in use today, to ensure an equitable distribution of seats at the parliament.

Victor D'Hondt, born in 1841, was a Belgian lawyer and a lecturer and mathematician at the University of Ghent. In 1882, he published his Système pratique et raisonné de représentation proportionnelle, which would meet a very specific objective. It is in this work that he developed a mathematical formula for the equitable distribution of seats in the Belgian Parliament, between Catholics and Liberals and between the country's different linguistic communities.

This "D'Hondt" method is still used for legislative elections in several countries, including Japan, Australia, Spain, Paraguay and – of course – Belgium; it is also used for the European elections. In the United States it is known by another name, the Jefferson method. Victor D'Hondt continues to influence proportional elections, even though he died in 1901.

The D'Hondt method involves giving each list a number of seats proportional to its number of votes. Let's use Belgium as an example to explain how the formula works.

For regional, federal and European elections (with the exception of municipal elections, which use the "Imperiali" system), the number of votes obtained by each list is divided successively by 1, 2, 3, etc. The results, called "quotients", are then ranked in descending order until as many quotients have been reached as there are seats to fill. The last result of this list becomes the "electoral divider". This is the number by which a party's total number of votes must be divided to find out how many seats it has won (by rounding down). Elementary, my dear Watson!