Fig 1.
Study extent of census tracts analyzed for the Boston MSA (A,B,C) and Phoenix MSA (D,E,F). Darker blue indicates (A,D) higher percentage white residents, (B,E) more completed eBird checklists, and (C,F) higher median household incomes.
Table 1.
Summary statistics by census tract for BOS and PHX MSA hypothesized predictor variables.
Fig 2.
Model averaged relationship between median household income and predicted number of eBird checklists per tract in the Boston Metropolitan Statistical Area (BOS MSA).
Gray ribbon indicates estimated standard error bounds.
Fig 3.
Model averaged relationship between proportion of white residents and predicted number of eBird checklists per tract in the Boston Metropolitan Statistical Area (BOS MSA).
Gray ribbon indicates standard error.
Table 2.
Model averaged parameters for BOS and PHX MSA total eBird checklists by predictor variables.
Fig 4.
Model averaged relationship between median household income and predicted number of eBird checklists per tract in the Phoenix Metropolitan Statistical Area (PHX MSA).
Gray ribbon indicates estimated standard error bounds.
Fig 5.
Model averaged relationship between proportion of white residents and predicted number of eBird checklists per tract in the Phoenix Metropolitan Statistical Area (PHX MSA).
Gray ribbon indicates estimated standard error bounds.
Fig 6.
Simulated data to demonstrate the statistical bias that can occur with unbalanced sample selection.
Panel A. Full sample with random, independent draws for biodiversity and income (β = -0.0042, SE = 0.031, p-value = 0.89). Panel B. Same sample with selection, where tracts with low income or low biodiversity are unobserved (β = -0.17, SE = 0.032, p-value < 0.001).