Method and sources

Where every number on this site comes from, and what it deliberately leaves out.

Source

California Department of Insurance, rate filing search (interactive.web.insurance.ca.gov). The index is a public database of filings; this site queries it month by month and stores the rows.

How it is collected

One query per calendar month per line. The database returns at most fifty rows per page and does not paginate through the URL, so a month-sized query is the only way to be sure nothing is cut off. If a month ever returns a full page, the run flags it.

What the number means

The requested rate change, as filed. Positive is an increase, negative a decrease. It applies to the company's own rates, so percentages are not directly comparable between companies of different size.

What is missing

The approved rate. Decisions live in the filing documents, not in the index, and only a handful of disputed cases ever reach a public hearing. Those cases are the ones where the difference between requested and approved is largest, which is exactly the difference this site cannot yet show for every company.

Also missing: how many policyholders a filing affects. A 60% request from a company with a thousand customers is not the same event as a 7% request from one with a million.

Coverage of this collection

Two personal lines are collected: homeowners multi-peril and auto liability and physical damage. Commercial lines, workers compensation and life are not included. The calendar years covered are listed on the front page, and the run is repeated monthly so that new filings appear without a rebuild of the checker.

Known gaps

Where a single month in a single line returns more than fifty records the run reports it rather than silently cutting the list. One such month exists in the current collection, and the warning is kept visible instead of being smoothed over.