Previous studies about the relationship between the cyclical components of Mexico's output and unemployment suggest that it closely resembles that found in the economy of the United States of America. This would indicate that the dynamics between output and labour markets in the two economies are rather similar. However, these estimates are puzzling for they do not correspond to a characterization made to Mexico's labour market. Using a methodology first proposed by Clark (1989), we find that the correlation between the transitory components of output and unemployment is much lower than previously thought.