In some sense, it doesn't matter whether population goes up or down, we should not have a policy that population must always go up. But for CA the problem is that wealthier people are leaving while poorer people are moving in. This is exarcebated by a policy of high income taxes and low real estate taxes -- real estate is much less mobile than people. And this is further exarcerbated by a policy of very progressive income taxes, which makes the state budget sensitive to a small number of wealthier households leaving.
change in population = migration from rest of word - californians leaving the state + births - deaths
In California, that means existing residents are moving out, people from the rest of the world are moving in. That has led to record low growth rates in 2019 (https://www.politico.com/news/2020/05/05/california-populati...) and an estimated population decline in 2020 (https://www.sfchronicle.com/bayarea/article/California-s-pop...)
In some sense, it doesn't matter whether population goes up or down, we should not have a policy that population must always go up. But for CA the problem is that wealthier people are leaving while poorer people are moving in. This is exarcebated by a policy of high income taxes and low real estate taxes -- real estate is much less mobile than people. And this is further exarcerbated by a policy of very progressive income taxes, which makes the state budget sensitive to a small number of wealthier households leaving.