Prosperity in Germany cannot be attributed to the simultaneous actions of two opposite principles.
Complete Works, Volume 2, pages 141 to 147 (in French)
In this article of the Journal des Economistes, Frédéric Bastiat responds to La Presse newspaper and its dithyrambic description of the implementation of the Zollverein before explaining how wise it would have been to not apply it to the production and importation of sugar.
The first part pertains to the issue of correlation and causation. If the prosperity that followed the Zollverein is real, La Presse attributes it to the tariffs that were implemented while Frédéric Bastiat attributes it to the abolition of commercial barriers within Germany. The situation is summed up by the following metaphor: “Germany had two arms tied up; the Zollverein was implemented and freed the right arm (domestic trade) while stifling the left arm a little more (international trade)”. Even in case there is disagreement on the causal link that led to prosperity, it is incongruous to attribute it to the left arm, to say the least!
Moreover, La Presse does not stop there and falls even more into contradicting itself when taking the protection on sugar (for which the objective was to produce beetroot sugar as a substitute to cane sugar imports) and exposing it as a mistake. Frédéric Bastiat obviously agrees with this denunciation. He shows that it applies as much to French iron substituting foreign iron, thus supporting his argument in favour of free-trade and his analysis, according to which the benefits of the Zollverein do not follow the tariffs closing the German market but the abolition of domestic restrictions between the various states constituting the German empire.