California’s tax code dates back to an era of lumber mills, tomato canneries and petroleum tank farms, a lunch-pail world that’s largely vanished as another one filled with personal services, banking and technology flourishes.

This creaking setup plays favorites and misses entire industries. It’s also to blame for Sacramento’s gyrating finances that wobble through recessions, surges and voter revolts such as the deeply unfair Proposition 13 enacted nearly 40 years ago.

This haphazard tax system is no secret. But adopting a modern, stable one will be an enormous undertaking, one of the reasons that state lawmakers from Gov. Jerry Brown on down have only chipped away at the crumbling structure, exasperated at the challenge of an overhaul.

State Controller Betty Yee, California’s elected bill-payer-in-chief, is nudging forward a report that could lead to a serious changes. Or it could waste away on a top shelf, another nice try that goes nowhere.

Yee is notably cautious, calling the document a framework with no recommendations. It was pulled together by 10 civic worthies, mostly from campus think tanks and study groups, after a year’s worth of discussion.

While lawmakers have peppered the tax code with 4,600 proposals over the past 20 years, hardly any amounted to comprehensive reform, the report notes. A scramble for yearly budget money, dug-in special interests and a lack of long-range vision are the main excuses.

The report pinpoints the central sore point of California’s finances: an overreliance on personal income taxes. Nearly 70 percent of Sacramento’s income comes from stock sales, real estate transactions and other earnings from a tiny group whose fortunes float up and down with the economy. It’s a system that amplifies the highs and the lows of each cycle.

There’s enormous appeal in sticking it to the rich. But when the stock market tanks or incomes drop, Sacramento suffers. “It’s like riding a tiger,” Brown said last month. State Sen. Robert Hertzberg, a Los Angeles Democrat, is working on a parallel course to Yee to drum up support for sweeping tax changes.

There is no shortage of ideas, but each comes with trade-offs. A split property tax roll would hit business holdings more strictly than homes. A sales tax on services such as legal advice or a doctor visit could bring in billions on untaxed areas that total $1.5 trillion in business.

But the exact workings need to be spelled out, a task spotlighted by the report. “How fair is the burden born by all the taxpayers?” Yee asked. The trick is finding a balanced formula that doesn’t harm economic growth in an ever-changing state.

Tax reform, in short, is a political minefield, a lobbyist nightmare and a touch unpredictable. Those are no doubt the reasons that Yee is pushing forward a report with no conclusions, just a 84-page recital of recent history.

It would be better if the controller, who is a veteran tax expert, would identify solutions and argue them convincingly. For now she’s going slow, asking the public to start thinking through the options. Yee also suggested that tax reform be a topic for a growing crop of gubernatorial candidates running to succeed Brown in 2018. That discussion can’t come soon enough in a tax-troubled state.