Table 2.

Prevalence of Intestinal Infections for Children under Five Using Alternative Baseline Periods.

	(1)	(2)	(3)	(4)	(5)	(6)	(7)
Period of Analysis	2009 vs 2008	2009 vs 2007	2009 vs 2006	2006–2009	2006–2009	Pre-2009	Pre-2009
Panel A. The Dependent Variable Captures Diarrhea-related Hospitalizationsa
H1N1b	−0.105	−0.218	−0.105	−0.143	−0.143	0.000
	(0.040)	(0.065)	(0.057)	(0.044)	(0.062)	(0.023)
p-valuec	0.060	0.140	0.202	0.089	0.105	0.998
R2	0.588	0.602	0.431	0.406	0.681	0.144
Mean $\left({\displaystyle \overline{Y}}\right)$	1,117	1,221	1,126	1,263	1,263	1,371
Obs.	64	64	64	128	128	128
State Trendsd	No	No	No	No	Yes	No
Panel B. The Dependent Variable Captures Diarrhea Cases (Morbidity)e
H1N1b	−1.737	−1.402	−1.480	−1.448	−1.540	0.061
	(0.786)	(0.897)	(0.933)	(0.540)	(0.663)	(0.210)
Seasonal Fluf							0.003
							(0.003)
p-valuec	0.051	0.295	0.101	0.058	0.000	0.788	0.121
R2	0.501	0.442	0.476	0.287	0.289	0.022	0.613
Mean $\left({\displaystyle \overline{Y}}\right)$	49,977	50,502	50,811	51,799	51,799	53,205	1,371
Obs.	64	64	64	128	128	128	96
State Trendsd	No	No	No	No	Yes	No	No

Notes: Columns (1), (2), and (3) are pairwise comparisons where the control period is 2008, 2007, and 2006, respectively, and the treatment period is 2009. For columns (4) and (5) the control period is 2006–2008 and the treatment period is 2009. For column (7), the treatment period is 2008, and the control period is 2006–2007. All regressions include time and state fixed effects. Mean $\left({\displaystyle \overline{Y}}\right)$ denotes the mean of the dependent variable for each specification and for the period of analysis.

^aThe dependent variable is the annual number of hospital discharges where the primary diagnosis was International Classification of Diseases (ICD-10) code A00-A09X (Intestinal Infections) for children under the age of five.

^bH1N1 is equal to the number of confirmed H1N1 cases in a given state in 2009 and zero otherwise.

^cp-value denotes the p-value of wild bootstrapped standard errors for a given specification to correct for small number (32) of clusters.

^dState Trends denote state-specific linear trends.

^eThe dependent variable is the number of diarrhea cases (morbidity).

^fThe treatment is denoted by “Seasonal Flu” which captures the number of seasonal flu cases in a given state and year.