The strong tax protest movement of the past two years was not enough to keep property taxes from rising in most Utah communities in 1988, according to the Utah Foundation.

The foundation, a private tax research organization, found that total property tax rates rose in 53 of the state's 71 largest cities and declined in only 18 cities this year.The average property tax rate for these 71 cities rose about 1.2 percent - from 1.5712 percent in 1987 to 1.5893 percent in 1988.

But the foundation said that effective property tax rates differ from those officially listed under the state's truth in taxation law.

That's because only state-assessed property, such as utilities, railroads and mines, and personal property, such as cars, machinery and equipment, are actually taxed at 100 percent of their value. Residential property is assessed for property tax purposes at 60 percent of its value, and other locally assessed property is assessed at 80 percent.

Using effective tax rates, state-assessed and personal property tax rates rose from 1.57 percent in 1987 to 1.59 percent in 1988; the rate for other locally assessed property went from 1.26 to 1.27 percent; and the rate for residential property rose from 0.94 to 0.95 percent.

Initiative A, which voters rejected in the November election, would have limited the effective rate for state-assessed and personal property to 1 percent, for other locally assessed property to 0.8 percent, and for residential property to 0.6 percent, the foundation said. These limits would not have applied to taxes needed to service existing debt.

School districts collect the largest chunk of property taxes, and this year 29 districts raised their tax rates, while eight districts reduced theirs and three left their rates the same as in 1987.

Fifteen counties raised their rates, while 14 lowered theirs. And of the 230 cities and towns that can impose property taxes, 137 reduced their rates, while 79 raised their rates and 14 made no change.

Property taxes are a function of two factors - the valuation of the property and the combined tax rates of the various taxing entities. Under Utah law, the state Tax Commission must order each county to adjust or factor its assessment rates to equalize valuations among the counties at the end of every even-numbered year. The next factoring order will be at the end of 1988, affecting 1989 property valuations.

In the past, property values have usually risen after a factoring order, but in the past few years Utah property values have been declining, the foundation report noted. In many instances, the report said, actual property values may be less than the values at which the property is being taxed.

"Preliminary indications are that the factoring order that will be issued this year will not result in significant valuation adjustments for most counties," the report said.