Principles of Sound Tax Policy

As a nonpartisan, educational organization, the Tax Foundation has earned a reputation for independence and credibility. All Tax Foundation research is guided by the principles of sound tax policy, which should serve as touchstones for policymakers and taxpayers everywhere.

Simplicity: Administrative costs are a loss to society, and complicated taxation undermines voluntary compliance by creating incentives to shelter and disguise income.
Transparency: Tax legislation should be based on sound legislative procedures and careful analysis. A good tax system requires that taxpayers be informed and understand how tax assessment, collection, and compliance works. There should be open hearings, and revenue estimates should be fully explained and replicable.
Neutrality: Taxes should not encourage or discourage certain economic decisions. The purpose of taxes is to raise needed revenue, not to favor or punish specific industries, activities, and products. 
Stability: When tax laws are in constant flux, long-range financial planning is difficult. Lawmakers should avoid enacting temporary tax laws, including tax holidays and amnesties.
No Retroactivity: As a corollary to the principle of stability, taxpayers should be able to rely with confidence on the law as it exists when contracts are signed and transactions are completed.
Broad Bases and Low Rates: As a corollary to the principle of neutrality, lawmakers should avoid enacting targeted deductions, credits, and exclusions. If tax preferences are kept to a minimum, substantial revenue can be raised with low tax rates. Broad-based taxes also produce relatively stable tax revenues from year to year.
Put simply, good tax policy promotes economic growth by focusing on raising revenue in the least distortive manner possible.