An additivity property of LM tests is derived, linking joint, marginal and Bera-Yoon `adjusted' tests, hence the latter can be derived as the difference of the first two. An artificial regression framework provides an intuitive geometrical illustration of the Bera-Yoon principle.

We provide evidence on the impact of a large construction of pre-primary school facilities in Argentina. We estimate the causal impact of the program on pre-primary school attendance and maternal labor supply. Identification relies on a differences-in-differences strategy where we combine...