Censuses and the Planning Fallacy: The Chilean Case

Abstract

The successful completion of a population and housing census is not simple. Because it is a major endeavor, numerous obstacles and barriers may be faced, and so there are many possibilities of errors. The origin of these errors is frequently not a lack of technical capacities, but erroneous decisions resulting from cognitive biases that induce excessive confidence regarding the amount of time needed to complete the different stages of a census, in the human and financial resources required to conduct them and in the coverage and reliability of the data to be produced. These erroneous decisions correspond to the so-called planning fallacy. There are several manuals and textbooks on the conduct and administration of censuses as well as vast accumulated experience. However, despite the importance of these manuals and experience, they have not been analyzed. The aim of this paper is to analyze how one of the mechanisms of the fallacy of planning can generate serious errors in a census. This is illustrated by the case of Chile where the 2012 census had serious problems. It is proposed that many of the errors that affected this census have their origin in cognitive biases that affected administrative, methodological and technical processes.