The Institute on Taxation and Economic Policy (ITEP) is a non-profit, non-partisan think tank that works on state and federal tax policy issues. ITEP was founded in 1980, and is a 501(c)(3) tax-exempt organization. ITEP describes its mission as striving to "keep policymakers and the public informed of the effects of current and proposed tax policies on tax fairness, government budgets and sound economic policy." Publications ITEP's flagship publication is its "Who Pays?" report. The report was originally released in 1996, and has since been updated in 2003, 2009, 2013, 2015 and 2018. The 2018 report includes tax changes enacted through September 10, 2018, at 2015 income levels. "Who Pays?" analyzes the distribution, by income level, of state and local taxes in all 50 states, as well as in the District of Columbia. Its main finding is that: "the vast majority of state and local tax systems are fundamentally unfair. An overreliance on consumption taxes and the absence of a progressive personal income tax in many states neutralizes whatever benefits the working poor receive from refundable low-income tax credits." The majority of the data contained in this report is produced using the ITEP Microsimulation Tax Model. Other major reports released by ITEP include "90 Reasons We Need State Corporate Tax Reform", which examines the effective state corporate income tax rates paid by large and profitable companies. "Building a Better Gas Tax" measures the impact of construction cost inflation in preventing most state gasoline taxes from providing a sustainable source of transportation revenue. "A Capital Idea" examines the revenue and fairness implications of state tax breaks for capital gains income, and "Writing Off Tax Giveaways" does the same for itemized deductions. ITEP also reports on "Undocumented Immigrants' State and Local Tax Contribution" made by nearly 11 million undocumented immigrants residing currently in the United States. Many of ITEP's reports deal with issues or proposals that are relevant to only a single state – often focusing on proposed tax changes or reforms, for example, "The ITEP Guide to Fair State and Local Taxes".<ref>The ITEP Guide to Fair State and Local Taxes. Institute on Taxation and Economic Policy.</ref> ITEP has released a series of reports criticizing studies by Arthur Laffer about the economic impact of lowering or eliminating state personal income taxes and estate taxes. Funders ITEP lists a number of foundations among its funders, including the Annie E. Casey Foundation, the Ford