TaxMath

Sources

Every external link in our articles comes from this catalog — 97 sources, ranked by authority. We reach for the statute and the agency that administers it first, and for research organizations only where no government publishes the comparison. Each entry lists the articles that rely on it, so a source that moves or goes stale can be traced straight to the claims it supports.

How we rank sources

  1. 1. Primary law The law itself: public laws, the tax code, regulations, executive orders, and court opinions.
  2. 2. Government The agency that administers the tax: IRS and Treasury guidance, forms and instructions, state revenue departments, official statistics.
  3. 3. Official record Legislative and budget record: bill trackers, enacted-bill pages, and nonpartisan scorekeepers such as the JCT and CBO. Authoritative about what was passed, not about how it is administered.
  4. 4. Research Nonpartisan policy research and multi-state surveys — used for comparisons no single government publishes.
  5. 5. Industry Practitioner and trade analysis. Cited only for market facts, never for what the law says.
  6. 6. Press News reporting. Last resort, for events not yet reflected in an official source.

Primary law

The law itself: public laws, the tax code, regulations, executive orders, and court opinions.

Government

The agency that administers the tax: IRS and Treasury guidance, forms and instructions, state revenue departments, official statistics.

Official record

Legislative and budget record: bill trackers, enacted-bill pages, and nonpartisan scorekeepers such as the JCT and CBO. Authoritative about what was passed, not about how it is administered.

Research

Nonpartisan policy research and multi-state surveys — used for comparisons no single government publishes.