One of the immediate short term effects of the Attica prison riots was that the authorities could make the wrong call in a tense situation. The lack of faith in negotiating with the inmates and their demands, which by today's standards seem reasonable, was one of the short term effects of the riot. This helped to fulfill the narrative that police were more interested in using force and displaying their capacity for destruction more than working through problems peaceably and with an interest towards those who might not represents power and wealth. The use of power against the prisoners, especially in light of the number of dead inmates over hostages, represents how police might have gotten it wrong in addressing the situation. The immediate short term effect was to enhance an already emerging narrative that police did not hesitate is using and abusing their powers.
I would say that a longer term effect of the Attica prison riots was the need to reform the prison system. In the end, prison reform is not a topic most politicians would wish to address. Governor Rockefeller's refusal to even visit the standoff and take charge of it represents this. Attica demonstrated how prisoners can demonstrate cohesion and overpower the guards if they feel their needs are not being met or if they are the targets of abusive behavior by those in the position of power. The same problems that were faced in Attica in terms of how exactly to do address the issue of prisons without appearing "soft on crime" is relevant today. Politicians today still do not demonstrate the moral courage and the political savvy to address the issue of prison reform. While prisoners' rights have increased since Attica, the same reluctance to take a comprehensive and meaningful look in examining America's prisons still remains. While America has not seen the likes of an Attica uprising since, the reality is that the same combustible elements might be still there, helping to confirm the long term effects of the riot are inescapable.