Labrousse’s two investigations of cereal price movements (Labrousse 1933, 1944) suggest a sort of dualism in the arguments put forward in the two works (Morineau, 1966). Using contemporary data analysis and cliometrics, we propose to test different hypotheses that emerge from our reading of Labrousse (1933 and 1944). The first set of hypotheses relates to the long-term movement of grain prices. The second type of hypothesis relates to price cycles and price volatility. The originality of our approach in part relates to the very long runs of data drawn from different sources. Results of our study of the wheat price evolution partially questions Labrousse’s analysis.