Finance will be among the priority concerns when the United Nations Convention on Biological Diversity launches the post-2020 framework for global biodiversity conservation (Global Biodiversity Framework) in 2021. The Biodiversity Finance Initiative provides a means for countries to account systematically for their biodiversity expenditures. A sample of 30 countries facilitated the construction of a panel to better understand the effectiveness of public biodiversity investments. Overall, the results show a positive trend in national public biodiversity investments and that larger economies invest more in biodiversity in gross magnitude and as a percentage of gross domestic product (GDP) (0.30% of GDP among wealthy countries versus 0.29%) and of national budgets (1.78% versus 1.14%). Controlling for GDP, wealthier countries invest proportionately less than less wealthy countries. The relationship between GDP and public biodiversity expenditure is an inverted-U curve. All biodiversity-related variables (threatened species, protected area and the presence of a hotspot) were positively correlated with public biodiversity investments. Funds allocated to biodiversity are associated with a reduction in the number of threatened species and the rate of biodiversity loss of about 1% per year. Each US$1 billion investment in biodiversity is associated with an annual reduction in the proportion of threatened to total species of about 0.57%. Population growth is associated with lower financial support for biodiversity and an increase in the proportion of threatened to total species in a country.