We also consider more parsimonious model specifications, such as the model that only considers within-city transmissions, 2 yct=∑τ=12αwithin,τy¯ctτ+xctβ+𝜖ct,and the model where the time lagged variables are averages over the preceding 2 weeks, yct=αwithin114∑s=114yc,t−s+αbetween114∑s=114∑r≠cdcr−1yr,t−s+ρ114∑s=114zt−s+xctβ+𝜖ct.Model B