Jan 19–Feb 29 Jan 19–Feb 1 Feb 2–Feb 29
(1) (2) (3) (4) (5) (6)
OLS IV OLS IV OLS IV
Model A: lagged variables are averages over the preceding first and second week separately
Average # of new cases, 1-week lag
Own city 0.747*** 0.840*** 0.939*** 2.456*** 0.790*** 1.199***
(0.0182) (0.0431) (0.102) (0.638) (0.0211) (0.0904)
Other cities 0.00631** 0.0124 0.0889 0.0412 − 0.00333 − 0.0328
wt. = inv. dist. (0.00289) (0.00897) (0.0714) (0.0787) (0.00601) (0.0230)
Wuhan 0.0331*** 0.0277 − 0.879 − 0.957 0.0543* 0.0840
wt. = inv. dist. (0.0116) (0.0284) (0.745) (0.955) (0.0271) (0.0684)
Wuhan 0.00365*** 0.00408*** 0.00462*** 0.00471*** − 0.000882 − 0.00880***
wt. = pop. flow (0.000282) (0.000287) (0.000326) (0.000696) (0.000797) (0.00252)
Average # of new cases, 2-week lag
Own city − 0.519*** − 0.673*** 2.558 − 1.633 − 0.286*** − 0.141
(0.0138) (0.0532) (2.350) (2.951) (0.0361) (0.0899)
Other cities − 0.00466 − 0.0208 − 0.361 − 0.0404 − 0.00291 − 0.0235**
wt. = inv. dist. (0.00350) (0.0143) (0.371) (0.496) (0.00566) (0.0113)
Wuhan − 0.0914* 0.0308 3.053 3.031 − 0.154 0.0110
wt. = inv. dist. (0.0465) (0.0438) (2.834) (3.559) (0.0965) (0.0244)
Wuhan 0.00827*** 0.00807*** 0.00711*** − 0.00632 0.0119*** 0.0112***
wt. = pop. flow (0.000264) (0.000185) (0.00213) (0.00741) (0.000523) (0.000627)
Model B: lagged variables are averages over the preceding 2 weeks
Own city 0.235*** 0.983*** 1.564*** 2.992*** 0.391*** 0.725***
(0.0355) (0.158) (0.174) (0.892) (0.0114) (0.101)
Other cities 0.00812 − 0.0925* 0.0414 0.0704 0.0181 − 0.00494
wt. = inv. dist. (0.00899) (0.0480) (0.0305) (0.0523) (0.0172) (0.0228)
Wuhan − 0.172* − 0.114** − 0.309 − 0.608 − 0.262 − 0.299*
wt. = inv. dist. (0.101) (0.0472) (0.251) (0.460) (0.161) (0.169)
Wuhan 0.0133*** 0.0107*** 0.00779*** 0.00316 0.0152*** 0.0143***
wt. = pop. flow (0.000226) (0.000509) (0.000518) (0.00276) (0.000155) (0.000447)
Observations 12,768 12,768 4,256 4,256 8,512 8,512
Number of cities 304 304 304 304 304 304
Weather controls Yes Yes Yes Yes Yes Yes
City FE Yes Yes Yes Yes Yes Yes
Date FE Yes Yes Yes Yes Yes Yes