Table 2. Results of Spearman correlations between various types of nature exposure (1^st column) and conservation NGO revenues.

Type of Nature Exposure	Category	Correlation With Conservation NGO Revenues (ρs)	Lag time (years)	Pos./Neg. Correlation	P	N
State Park Visitation	Visitation	−0.74545	4	Neg.	*	15
National Park Visitation	Visitation	−0.51892	4	Neg.	*	27
National Park/National Forest Camping	Visitation	−0.53431	7	Neg.	*	12
Backpacking/Hiking (Mediamark)	Hiking	0.80588	11	Pos.	***	8
Appalachian Trail Hiking	Hiking	0.61538	11	Pos.	*	27
Backpacking (Statistical Abstracts)	Hiking	0.90000	12	Pos.	*	6
Bureau of Land Management Visitation	Visitation	−0.67273	15	Neg.	*	9
National Park Visitation	Visitation	−0.85000	17	Neg.	**	27
Fishing	Visitation	−0.80952	17	Neg.	*	27

^*indicates significant at 0.05 level, ** indicates 0.01 level, *** indicates 0.001. Correlations were performed for all possible lag periods in years. For example, results in the 1^st row (State Park Visitation) indicate that there was a significant, negative correlation between state park visitation and conservation NGO revenues 4 years later (Spearman's rho  = −0.74545, P<0.05, N = 15 comparisons. As state park visitation increased, NGO revenues decreased 4 years later. Conversely, as time spent backpacking/hiking (taken from the Mediamark series) increased, NGO revenues increased 11 years later. The table illustrates that the effect of public lands visitation (including fishing, shaded areas) had a negative effect on NGO revenues with two distinct time lags, 4–7 years later and 15–17 years later; while backpacking/hiking had a positive effect on NGO revenues 11–12 years later.