Belgrade — Even though they acknowledge that economic inferiority was the root cause of a year of unrest in Kosovo Province, Yugo-slav authorities are waving a political fist at that troubled southern region.
More than 60 ethnic Albanians have been jailed this month for terms ranging from one year to the maximum 15 years. They were allegedly behind clandestine groups agitating for an independent Kosovo republic within the federation.
In more than 55 trials of ''hostile groups'' since the riots of March 1981, some 700 people have been sentenced. As many more have lost teaching and other posts.
A thousand have been expelled from the local branch of the Yugoslav Communist Party for sympathizing with the ''independ-entists'' or failing to take a stronger stand against the calls for cession from Serbia, the biggest Yugoslav republic. Kosovo is an autonomous province within Serbia.
But the stiff jail sentences handed down since the party congress in late June seem at variance with official admissions that Kosovo's troubles were largely fired by its economic backwardness. The living standard of its majority ethnic Albanian population is still far behind the rest of the country.
''Grave economic errors were made,'' a Kosovo delegate said. ''High investments were put into noneconomic facilities and the (essential) processing industries and small-scale economy were neglected.''
That is beginning to change. Twenty-two projects have been announced, mainly to develop irrigation and food industries, including the province's first chicken broiler unit.
But the latest convictions show those directly involved in last year's rioting receiving severe sentences. It could be counter-productive.
Currently, Kosovo is quiet - at least on the surface. The provincial capital is still patrolled night and day by police (always in pairs). The Army stands by out of sight.
Summer evenings have seen young people resume their traditional ''corso'' strolling on the main street. Many older people stay home after dusk.
Serbs - on last year's census 13.2 percent of the population compared with the ethnic Albanians' 77.5 - still occasionally find a menacing daub on their front door.
The reciprocal bitterness is such that, in the past 10 years, nearly 70,000 Serbs have migrated from an area all Serbs revere as their homeland since the 7 th century.
The bitterness prompted the apprehensions and harshness of Belgrade's initial reactions - despite other republics' calls for moderation - to last year's protests. It led to violent polemics with neighboring Albania, which Belgrade accused of aiding the Kosovo extremists.
Outsiders question to what extent, if any, that might have been so. Albania recently moderated its tone, and the two countries have called a truce to polemics, concentrating instead on such things as the building of the first rail link between their countries.
The Albanian party newspaper Zeri i Popullit July 14 denied concern in Kosovo's affairs beyond sympathy with its ethnic majority's continued economic inferiority and its demands for equal treatment and status with the republics.
Belgrade's opposition to republican status for Kosovo does not seem consistent with Tito's old rallying cry of brotherhood and equality. One wonders how long his successors can reject such a solution, however much they do to repair past neglects and speed up Kosovo's development in terms of consumerism and jobs for youths.
The average Yugoslav per capita yearly income is some $3,000. Kosovo's is only one-quarter of that. Kosovo's unemployment rate is the country's highest, and it is much higher among Albanians than Serbs.
Analysis within the province suggests that - as official sources claim - talk of ''union'' with Albania is limited to a few extremists. But interest in gaining republican status is widespread, especially among the young.