CARA, based at Georgetown University in Washington, D.C., has tracked U.S. seminary enrollments and priestly ordinations since its formation in 1964.
"One of the most stable trends in U.S. church data since the mid-1980s has been the annual numbers of diocesan ordinations" to the priesthood at around 400 a year, CARA said in its summer 2012 quarterly CARA Report, released in mid-August.
"This stable inflow each year is not enough, however, to compensate for the number of diocesan priests dying or departing the priesthood annually," it said.
In 2010, it said, new ordinations without counting deaths or departures amounted to a net loss of 301 diocesan priests -- a trend that has continued over many years, causing a significant decrease in the priests serving the nation's parishes.
"These losses accumulate each year creating a running deficit in the number of diocesan priests," the report said. "Some dioceses deal with this shortfall, in part, by bringing in international priests who have been ordained outside the United States."
While U.S. ordinations have stabilized at around 400 a year, "the church needs more like 700 per year to establish stability in the numbers of U.S. diocesan priests overall," CARA reported.
"This is an attainable goal," CARA said.
"CARA research has found there is no shortage of Catholic men who say they consider the priesthood, but still few who follow through to become priests," the report said.
Only about one out of every 100 Catholic men who have ever "very seriously" considered priesthood has gone on to enter a seminary, CARA research shows.
"If the church could just increase that to two or three in every 100 ... concerns over the priest shortages would end," it said.