Add to ORKGWe present the results of an experiment measuring social preferences within couples in a context where intra-household pay-off inequality can be reduced at the cost of diminishing household income. We measure social norms regarding this efficiency-equality trade-off and implement a cross-country comparison between France and Germany. In particular, we show that German households are more inequality averse and are thus less efficient than French households. A decomposition of this difference reveals that approximately 40 % is driven by diverging sample compositions in the two countries, while 60 % of the initial French/German difference remains unexplained. Beliefs differ significantly from observed behavior in both countries. Efficient choi...