The final map in the Tax Foundation’s four-part series highlights corporate income taxes and their share of state and local tax revenue. The corporate income tax makes up a much smaller share of total national tax collections, 3.7%, than any of the other taxes analyzed thus far.

New Hampshire, without a sales tax or a tax on wages, relies most heavily on the corporate income tax. At 9.3%, New Hampshire beats out Delaware, 9%, and Alaska, 8.8%, who likewise do not collect statewide sales taxes. Six states do not levy a corporate income tax: Nevada, Ohio, South Dakota, Texas, Washington, and Wyoming.

Oklahoma ranks 34^th nationally with corporate income taxes making up 2.7% of total state and local tax collections. From a regional perspective, this 2.7% places Oklahoma right in the middle—well below Arkansas and Kansas but above Missouri and Texas.

The corporate income tax is one of the most volatile revenue sources for state government. During economic downturns, businesses may record low profits or losses resulting in no tax liability and thus no revenue from this source for the state. Oklahoma has suffered from this volatility, leading to discussions of removing the tax all together. The Organisation for Economic Co-operation and Development (OECD) has also noted in a study that the corporate income tax can be particularly harmful to economic growth.