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

*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 1st 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.