( CNN ) -- The wide avenues of Havana became a colorful mosaic of the faces and flags of throngs of Cuban people -- 600,000 of them , according to state media -- as people gathered to commemorate International Workers ' Day , or May Day , on Sunday . But with the recent announcement of possibly sweeping , dramatic changes to Cuba 's economic system , and the difficulties international media face in speaking to Cubans , it is difficult to know with certainty what the mood on those streets is . Two days ago , Cuba 's state-run Granma predicted that today 's parade would be a `` brilliant culmination of the popular mass participation of workers and people in the open and democratic process of discussion '' that yielded the recent announcement of economic changes following the Sixth Party Congress of mid-April . But if mood and turnout at the parade were predictable , it was precisely because `` Cuban workers are told by the government to march on May 1 , and then afterwards , the Cuban government decides what the people were marching for , '' said Tomas Bilbao , executive director of the online Cuba Study Group , a site dedicated to the opening and reform of Cuba 's society and economy . Bilbao says similar turnouts in previous years have officially been attributed to other reasons . But given compulsory attendance and the lack of full , transparent information among Cuban people , he finds efforts to attribute large turnouts to people 's strong political feelings misleading . An end to those classic cars in Cuba ? Less than two weeks ago , Cuba 's Communist Party held its Sixth Party Congress -- its first in 14 years -- and announced that it had approved drastic changes , including term limits for its top leaders , the gradual elimination of the ration card system , the purchase and sale of housing and cars , and massive layoffs , which the president has said will exceed one million . Among average Cubans , neither the timetable of implementation nor the final details of these changes are known . It is not even clear if they will be formally announced at some future time . This leads to a cautious , if optimistic , uncertainty , Bilbao said . `` There is a lot of anticipation because people are in a desperate situation . But a lot of the fear is from people who will lose state jobs , or people concerned with losing elements of the ration system , especially older people . People are curious ... because in the past , these types of reforms have been rolled back . '' `` Plans are still to lay off 500,000 workers in the next few months , and one has to wonder how many of those who attended ( the May Day commemorations ) are doing so in the hope of avoiding that fate , '' said Eusebio Mujal-Leon , director of the Cuba XXI Project at Georgetown University in Washington , D.C. Bilbao says the timing of the Sixth Party Congress is indicative of a lack of party confidence : By preceding the Congress with the 50th anniversary of the Bay of Pigs invasion , and following the Congress with May Day marches , the party maximized nationalist sentiment and the appearance of massive popular support . And as to why the Congress would happen this year , as opposed to previous years , Bilbao said the desire for change has simply grown too strong . `` It 's no longer taboo in Cuba to recognize that the system has failed . ( President ) Raul Castro has encouraged people to debate what measures should be taken , '' Bilbao said of the possibilities of real reform . `` More importantly , '' he added , `` there is no alternative . ''
Official Cuban media : 600,000 people from Havana gathered at the capital 's Revolution Square . Comment: Around the world , May Day has historically brought displays of support for Communism and socialism .