I read it and really liked it and it reminded me of one of my favorite books is Alas Babylon that AROTC mentioned.
I believe that both authors while writing good stories are looking at the overall picture thru rose-colored glasses. I don't think it would be so long before FEMA got involved and marshal law would be almost immediate. They also had the grocery stores running (at lowered a capacity). The way the real world works in larger cities they would be closed and ransacked within days of the announcement of the EMP. Some communities will pull together and mount decent defenses but even subdivisions around a major population center were able to mount defenses they would be quickly overrun by shear numbers of people demanding food and shelter. I say demanding because large urban centers have to many people that are dependent on others to care for them. Also there will be to many who will see it as an opportunity to rape, pillage, plunder, and rape. Cohesive groups won’t really form until it sinks into the heads of people that thing won’t return to normal tomorrow.
I have seen how people react in stressful situations. Most of the good people will wait to act in a way that may be against the normal laws and morals of our society till they are forced to act. While they wait and watch the ones that don’t care will react to take advantage of the situation.

History is the proof of what you say, with VERY few exceptions.

If you aren't very good about spraying weed killer on your lawn (like me) then you will find out very quickly that Mother Nature will fill your yard with wild edibles. Chickweed & dandelions account for about a 1/3 of my front lawn. I've noticed in the city here the poor neighborhoods yards are almost all full of those two as well as wild onions, wood sorrel, etc.

Has anyone found the final chapters of "the decline and Fall Of Pax Americana"? I have up to chapter 60 but I can't find the rest.

I've read both Lights Out and Patriots, as well as other fictional works in this gendre. I find them an interesting read, but limited in scope. Sticking with the two books named herein, the authors explore a couple different "plausible" scenarios, with somewhat variable results. Overall, my conclusion is that both of these books, as well as most of the other stories in the gendre, fall far short of painting what would be the most likeliest of outcomes. Rather, they occupy a narrow slice of possibilities resulting from a very limited course of events.

After many discussions and analyses, I would expect a far different likelihood to occur. One of three most likely events will occur should our social structure as it stands today collapse. Either we face an abrupt end of the world scenario, such as global catastrophy like 2012 or some such, or a more gradual end of the world scenario, such as in the book "The Road", or general social collapse and post anarchic social engineering, such as Orwell's "1984" or Lucas' "THX-1138". I realize this sounds defeatist, but consider our current social model to be a line of dominoes, and realize how hard it is to stop a line of dominoes from toppling over in succession once the first few have gone. Either things get unrecoverably bad very quickly, or things get unrecoverably bad but it takes time for the stockpiles to run out, or things get very bad, and the only thing to keep it from going too far is extreme social control.

If you consider the outcomes in both stories, you realize very quickly that the authors chose to severely limit the unilateral response from those in power and able to exert control over the gen pop, at least as long as supplies hold out. They painted the executive role as poorly equipped and generally incompetent. While I would entertain the notion that the government may not have the same set of response priorities the common man would prefer, I would advice against anyone considering that they would restrict their response to any threat in some limited role. Their usual pattern of force reminds me more of using a sledgehammer to drive a brad. Letting a region fend for itself and stand on it's own volition seems rather unrealistic, considering that the biggest hoarder of resources in times of crisis are the feds themselves. I would expect more of a "no stone left unturned" type of policy.

Anyone who thinks that the government wouldn't take advantage of the opportunity to overwhelmingly respond to any threat, real or imagined, and to seize as much power as possible needs some remedial study in world history. As with 9-11, the fed response to the threat was to begin shutting down infrastructure and mobilizing for crowd/migration control.

They also seem to miss the role of modern technology. Drones with less-than-lethal weapons, as mentioned in this wired article, are on the way. A couple of drones could easily disperse a crowd of wrongdoers. How does the saying go? A surveilled society is a polite society? Something like that.