Table 9.

Difference-in-difference for quarterly sales growth: COVID-19, vaccine, and Olympics.

	(1)	(2)	(3)	(4)
	Sales	Sales	Sales	Sales
	growth	growth	growth	growth
VARIABLES	Q1–Q4	Q1–Q4	Q2–Q4	Q2–Q4
After zero new infection	2.18***	2.47***	2.48**	2.29**
	(0.82)	(0.90)	(1.01)	(1.00)
After zero new infection (t+1)	0.80	0.53	0.61	0.46
	(0.76)	(0.82)	(0.87)	(0.87)
After mass use of vaccine	0.37	0.31	0.54	0.49
	(0.85)	(0.87)	(0.93)	(0.92)
After mass use of vaccine (t+1)	2.41***	2.33***	2.33**	2.32**
	(0.81)	(0.88)	(0.99)	(0.97)
P(Olympic) $\times$ Q3	3.15*	3.15*	2.58	3.42*
	(1.61)	(1.61)	(1.88)	(1.90)
P(Olympic) $\times$ Q4	5.37***	5.46***	4.92**	5.71**
	(1.81)	(1.83)	(2.23)	(2.25)
Observations	24,125	24,125	18,017	18,017
Firm FE	YES	YES	YES	YES
Quarter FE	YES	YES	YES	NO
Optimism proxiy	NO	YES	NO	NO
Industry-Quarter FE	NO	NO	NO	YES

Notes: This table uses the panel data of quarterly firm sales growth in Q1–Q4 or Q2–Q4 in 2020. Sales growth in Q1 is the realized value, while sales growth in Q2–Q4 is expectation by the business owner. The observations are weighted to match the number of firms in the Economic Census. Standard errors are clustered at the level of firms. “Mean Qk” (for k = 2, 3, 4) shows the mean of the expected sales growth in Q3 and Q4 in the sample (respectively).