This paper revisits Ernst Engel's (1857) original article in which he systematically in-vestigated the relationship between consumption expenditure and income. While he ismainly remembered today for the discovery of Engel's law, we highlight how Engel ad-dressed in a particular way the issue of the relation between statistical empirical analysisand economic theorizing. Inspired by an inductive methodology, Engel's method to inferempirical regularities made no a priori assumption on the estimated functional form andanticipates many aspects of current non-parametric regression methods. Furthermore,Engel devised a quasi-behavioral theory of consumption centered on the concept of wantsto justify and explain his empirical results which he used to asses population living stan-dards. Although incomplete, Engel's consumption theory tackles a much neglected issuein consumption theory: what accounts for the manner in which consumption patternschange as income rises...
