First off: In CA we have prop 13, which prevents CA assessor from taxing your home based upon current appraisal (it's limited to a rate increase based upon your purchase price.) This was done in the 70's because people were forced to sell their homes to pay taxes. I know this as fact because it happened to my grandparents in Los Angeles. Prop 13 remains law because even in CA, it is realized as completely unfair to homeowners whose only crime was they paid off homes and lived a long time.
Prop 13 was one of the most poorly thought out laws in California's history, and its effects have been largely negative. Because of prop 13, taxes on property owned by business don't increase over time.
This artificially decreases rents and makes it more expensive to buy property, which decreases the incentive to build housing that is sold, rather than rented, which increases the cost of buying a house and makes more and more Californians dependent on perpetually paying rent for the rest of their lives.
This artificially decreases the portion of state revenue paid by businesses and increases the percentage paid by individuals.
This artificially decreases city and county tax revenue in cities that have a large commercial footprint or large amounts of rental property, again shifting the burden for schools, libraries, and other local services to individuals and away from the wealthy businesses that call those cities home.
This massively discourages people from selling their homes and moving closer to where they work which not only decreases supply and effectively drives up the cost of home sales, but also massively increases the amount of traffic on our highways.
Everything about Prop 13 was wrong. It was a stupid law passed by people who did not think through the consequences. Contrast with Tennessee's property tax freeze program, which allows anyone who is disabled or over 65 and meets certain income limits to freeze their property taxes at the current level. It still has the same intended effect — ensuring that people don't lose their homes when they retire — but without all of the negative side effects. With the level of income inequality in California, the age limit part might not be the right thing to do, but limiting it to your primary residence, excluding commercial and rental property, and possibly even an upper income threshold should be on the table.
Unwinding it safely will have to be done carefully, though. The potential exists for absolute carnage if the exemption gets removed for rent-controlled apartments, or worse, for rent-controlled mobile home parks. So there would still have to be a limited set of exemptions for certain qualifying business property for a period of time, then gradually shift to a less exempt rate. And maybe that would need to happen for all commercial property. Hard to say.
But either way, it needs to be completely rethought.
Second, If you've been through IPO you would know this: You will look in your portfolio account and see some really nice 7 figure numbers. But you will be blacked out for minimum 90 days and in some cases 180 days. You are only allowed a small window to exercise.
Blackout periods exist for all stocks owned by employees, thanks to insider trading rules. They're not limited to IPOs.
This is, of course, utterly irrelevant. When I get a property tax bill on my house (in California), I get the property tax assessment in June. The *bill* comes in October. The first half is ostensibly due in November, with penalties if it is not received by mid-December. The second half is due in February, with penalties if it is not paid by mid-April. So after the assessment, there's a six-month grace period for the first half of the money owned, and a ten-month grace period for the second half.
And government isn't going to be able to tax the value of IPO stock instantly anyway. They'll know what the value was on a particular date. So unless your stock IPOs exactly on that date and you have a 180-day blackout period (really freaking unlikely), that blackout period will be over before the first half of your payment is due.
And if that's not good enough, just write the law so that employee stocks and options do not get taxed until after the one-year anniversary of their vest date or after any post-vest/post-IPO blackout period, whichever is later. And you're done.