For the past 15 years, cities have focused on attracting the creative class. The idea is that if you build a thriving creative culture -- vibrant communities of artists, writers, musicians and so on -- a thriving economy will follow. It’s a strategy that’s worked well, especially in places like Asheville, N.C.; Denver; and Seattle.

In many cities, it’s worked too well. Some creative-class cities have become victims of their own success, unable to keep up with demand for housing, local public services and livable-wage jobs for the lower-middle class. The result is a crisis of affordability driven by huge spikes in home prices, rents and homelessness.

Local leaders have taken steps to respond. In the past 18 months, Los Angeles, San Francisco, Seattle, Silicon Valley in Santa Clara County, Calif., and other localities have proposed new local taxes to expand affordable housing and bolster services for the homeless. As they grapple with this new challenge of affordability, they must also confront an old question at the heart of local public finance: Who actually pays local taxes?

There are two ways to think about who pays. One is the “statutory incidence,” or who is required to remit a tax to the government. The other is the “economic incidence,” or who pays a tax because they’re unable to avoid it. The former is easy to measure. The latter is not.

Most local governments have access to the sales tax and the property tax. There’s good evidence that the economic incidence of the sales tax is on consumers. Merchants collect and remit the tax, but consumers pay it because there’s really no way around buying basic items like clothing. If the goal is for tourists to help pay for local affordability, then the sales tax makes sense. However, for that same reason poor and middle-income people also pay a larger share of their incomes in sales taxes compared to the rich because the sales tax is regressive. For many affordability advocates, that’s unacceptable. Why pay for affordability with a tax that falls disproportionately on the poor?

That’s why affordability advocates have warmed to the property tax. Middle- and upper-income people are more likely to own property and pay property taxes, so the statutory incidence is inherently less regressive. But if we care about economic incidence, the reality is unclear at best. In fact, for more than 50 years public finance experts have argued over who actually pays the property tax.

One school of thought says it’s really a tax on wealth. But higher property taxes might work against affordability by reducing the demand for housing and discouraging density. Why? It’s easy to imagine a homeowner who decides not to add on a new guest room because that will increase property value and the subsequent property tax bill. The same might apply to a landlord who opts against building a new rental property.

Another view says local property taxes are what you pay for the services your local government delivers. This is especially true for zoning, public safety and other services that benefit all property owners in roughly the same way. If that’s true, then property taxes are neither progressive nor regressive. Everyone pays a proportional amount for a proportional share of benefits.

Yet another view says the property tax is a tax on the service called housing. In that case, the property tax is like the sales tax. Since lower-income people cannot escape paying for housing (usually as renters) then property owners can send much of the property tax burden down the income ladder.

We’re not likely to settle this question any time soon. So for now, the question of who should pay for affordability will be about perceptions, priorities and politics, and not about public finance.