To make it easier to interpret the coefficients, we assume that the transmission dynamics (αwithin,s, αbetween,s, ρs) are the same within s = 1,⋯ ,7 and s = 8,⋯ ,14, respectively, but can be different across weeks. Specifically, we take averages of lagged yct, yrt, and zt by week, as y¯ctτ=17∑s=17yct−7τ−1−s, y¯rtτ=17∑s=17yrt−7τ−1−s, and z¯tτ=17∑s=17zt−7τ−1−s, in which τ denotes the preceding first or second week. Our main model is 1 yct=∑τ=12αwithin,τy¯ctτ+∑τ=12αbetween,τ∑r≠cdcr−1y¯rtτ+∑τ=12ρτz¯tτ+xctβ+𝜖ct.Model A