Over the past few years, there has been considerable interest in the subject of ‘collapse’, whether it be the collapse of America as a superpower, economic collapse, or the collapse of civilization, in general. Reddit even has a popular sub devoted to discussing collapse, appropriately named /r/collapse, which has become a sub-culture in its own right. I suspect the rise of ‘collapse-ism’ has to do with dissatisfaction of the status quo and a longing to ‘reset‘ society to a simpler and more ‘wholesome’ time, rather than they hyper-competitive, winner-take-all economy we have presently. Rather than the economy merely being an appendage of American society, it is society. Based on the empirical and historical evidence, and my own knowledge of the matter, my ‘thesis’ is that there won’t be collapse of America and its economy, but I want to address some the common ‘collapse’ arguments and also explain why America is so resistant.
According to records, civilizations last a couple hundred years , so will America suffer a similar fate? Not necessarily. There is a huge amount of variance of survival times, and the definition of what constitutes an intact, cohesive civilization is subjective. Rome is a thriving city despite the Roman Empire falling in 400 AD. The Western part of the Empire became the Holy Roman Empire; the eastern parts became the Byzantine Empire. It’s no longer the ‘Roman Empire’, but Rome is obviously not gone and Catholicism is still the official religion, just as it was over a thousand years ago. Although the Ottomans sacked Constantinople, they weren’t able to advance beyond Vienna.
Similarly, although America is still intact as a sovereign governing entity, to some it has ‘collapsed’ because, demographically, due to immigration and other factors, it bears less much resemblance to how it was hundreds of years ago. In a sense, America has been conquered, albeit very slowly and nonviolently. IMHO, that sounds like moving the goalposts, redefining collapse to mean something it isn’t. Collapse, in my mind, means the economy collapses, such as during the Great Depression or the economy of Germany at the end of WW2 or WW1, not some contrived definition concocted to fit a preexisting agenda. For example, Berkshire Hathaway bears no resemblance to its original textile business (before Warren Buffett bought it out); does that mean it has collapsed? Hardy; it’s doing better than ever. Apple, up until a decade ago, was considered to be primarily a personal computer company; the iPod and then later the iPhone changed that, and although Apple still sells a lot of personal computers, their main business is iPhones. For America to collapse means it would have to become a shadow of its former self. But that hasn’t happened: according to a wide variety of metrics–GDP, stock market gains, global influence, geopolitical stability, technological innovation, military might, strong currency, etc.–America is stronger and more influential than ever. America is the glue that holds the world together. Europe has been sluggish since 2008 , yet the US the economy has done fine since then.
But how about immigration and changing demographics? I don’t share the optimism of Bryan Caplan and Tyler Cowen in that regard, but the economic contributions of America’s high-IQ immigrants, especially in the tech sector, are probably enough to offset the drain of the less productive ones, at least for now. 51% of all U.S.-based startups currently worth over one billion dollars were founded by immigrants. Even ultra-conservative monarchies such as the UAE seek skilled foreign labor, but are painstakingly careful in preventing the problem America has now, where everyone and their family are allowed entry and not much is done about it. The UAE only has a guest worker program, and citizenship is only offered to foreigners in very special circumstances (it’s virtually impossible). Foreigners are not not allowed to buy property either. The only obvious downside is that such restrictive policies may discourage foreign investment (given that their entire economy runs around oil, once that runs out they are going to need all the help they can get). America is like a ‘magnet’ for the ‘best and the brightest’ from all over the world; first, Italian and German scientists after the second world war, and then during the Cold War, high-IQ Russians and Chinese. America is a like a fantasy sports team that gets the best players from all the teams in the league. But this also means the demography of America has changed dramatically over the past half century, and such change is also permanent.
The question is, what happens if there is too much immigration, especially the wrong type of immigration. This leads to dysgenic argument as outlined by West Hunter in a post Dysgenisc. However, I don’t share his concern.
From the comments:
High IQ individuals, like any other individuals practice assortative mating and are not restricted to rural areas of long labour days anymore. High IQ individuals also have a longer time-horizon for planning and considerations of unseen risks, obstacles and challenges. They also collectively tend to mate less, and/or delay fornication the higher their IQ when it competes with their pursuit of novel experiences and acquisition of knowledge, and if they do mate – they conceive at much lower rates, and if they do, have a fecundity of sub-replacement levels (~1).
Provided high-IQ people are able to self-segregate from low-IQ ones, dysgenics should be kept under control.
Economists may argue that America owes its success to a combination of the Puritan work ethic, free market capitalism, private property, and ‘rule of law’. But then why has America done so well when other counties also have laws, free markets, and property rights, but have been far less successful. America’s economic dominance really began after WW2. In aftermath of WW2 and the Cold War, Russia collapsed, as did Germany, Japan, Britain, France, Spain, and Italy, leaving America on top. And then with a dominant lead in 1990 (the end of the Cold War), America did not squander it. In just the span of a singe decade, it had the leadership of Clinton (who despite his ethical shortcomings, his neoliberal policies, for the time being, seemed to help) , the post-1990 revitalization of New York City under Giuliani, and the Silicon Valley tech boom. Although the tech boom imploded, it set the stage for the much larger post-2008 wealth creation boom that followed, because Silicon Valley and New York had established themselves as ‘hubs’ of cognitive and financial capital, creating a positive feedback loop of more and more capital. To get an idea of how important America’s technology sector is, the market capitalization of America’s five largest tech companies, combined, is the size of the economy of Brazil. Neoliberaism, both by Reagan and Clinton, gave America’s economy a boost of adrenaline following the 70’s and early 80’s stagflation, but it may also be America’s undoing should social decay and entitlement spending get out of control. 
But for America to collapse and cease being as dominant and influential as it is presently, it would probably require the majors epicenters of intellectualism and capitalism–New York, Seattle, Cambridge, and the Bay Area–be dethroned, if not outright collapse. For example, up until the 60’s-70’s, Detroit, Minneapolis, Cleveland, Baltimore, and Chicago were as important as New York is today, but a combination of race riots, capital flight, white flight, and the decline of the domestic auto industry irreparably damaged the economies of those cities. At the same time, New York was in the dumps, San Francisco was just another unremarkable city, and Silicon Valley was mostly unimproved farmland. But beginning in the 80’s—thanks to the technology industry, the digitization and financialization of the US economy, high-IQ immigration into New York and the Bay Area, and tons of cheap foreign capital—New York, Southern California, and the Bay Area saw a boom that continues to this present day, but Detroit never recovered. So could San Francisco, Silicon Valley, and New York collapse like Detroit, bringing the rest of the country with it? Unlikely. The reason has to do with IQ: whereas low-IQ regions (Brazil, Baltimore, Detroit, Chicago, etc.) and industries (auto, mining, construction, oil, etc.) have booms, they always end in nasty, prolonged busts. Always. Low-IQ countries and industries, due to corruption and incompetence attributable to low intelligence and high time preference, always squander their capital during the ‘booms’, which make the ‘busts’ really bad. But high-IQ regions and industries (with the exception of Japan and the dotcom crash) have booms which ‘plateau’ instead of bust. Rather than high-IQ regions, industries, asset classes, and countries permanently falling from grace, they stabilize, only to rise again when least expected.
The average length of time that a civilization lasts is 349.2 years. The median is 330 years. The civilizations that lasted the longest seem to be the Aksumite Empire which lasted 1100 years and the Vedic Period of India which lasted 1000 years.
 My ‘theory‘ is that America is in a tug-of-war between the ‘makers’ and ‘takers’, between forces of decay and creation, and so far the ‘makers’ are winning, but this can change. But the problem is, I cannot put a time frame on such a transition for when the ‘dependent class’ (SJWs, govt. dependents, BLM, etc.) gains the upper hand, even assuming it happens.