Before revision:  A key finding is that while the test based on the \infty\to1 norm requires relatively new tools from the semidefinite programming literature to implement, it can be substantially more powerful than that based on the 2\to2 norm for the kinds of sparse and degree-heterogeneous networks common in economics.
After revision:  A key finding is that while the test based on the \infty\to1 norm can be substantially more powerful than that based on the 2\to2 norm for the kinds of sparse and degree-heterogeneous networks common in economics.