Countries don’t break up every day, particularly those as large and prosperous as the United Kingdom of Great Britain and Northern Ireland.  But it is possible that, two weeks from now, the headline writers will be calling it the “Disunited Kingdom” if the Scots vote for independence in a referendum on September 18th.

For much of the year, markets have been ignoring the vote, largely because the No side has been consistently ahead. But the latest polls have been narrowing, putting the No vote just six points in front – within a plausible margin for error (remember all those 2012 polls showing Romney heading for the White House). Even a narrow No victory might be unsettling, implying the likelihood of a further vote in a few years’ time. So the markets are having to contemplate what the financial consequences might be; sterling recently reached a five month low against the dollar.

The issues, for those non-Britons who have not been following the debate, are fourfold. What currency will the Scots adopt? The Yes campaign says they will keep the pound, the Westminster parties say this is out of the question (essentially this would recreate the euro problem, in which monetary union would exist without political union.  The EU could insist, as it does with other new nations, that the Scots agree eventually to join the euro. The pro-independence group says EU spokesmen are wrong (Scots are already in the EU so would not be be new members) and that the English parties are bluffing. An independent Scotland can call the bluff of the rest of the UK by taking a hard line on the second big issue – the allocation of national debt. How should this debt be apportioned among the rump UK countries? By population? By GDP? If Westminster plays hard ball, the Scots could walk away altogether (although this sounds a bit like a bluff as well; the consequences for the new state would be stark, in the short term).

Both of these issues are big areas of uncertainty that will cause market concern if the Yes campaign wins. The remaining two financial issues are probably less market-sensitive but are still significant. How will the Scots manage their finances without the public spending support of the rest of the country?  Or as the pro-independence campaign would put it, how will the rest of the UK survive without the revenue support provided by Scottish oil? There could be some long and complex negotiations on these two issues.

Such negotiations may be made even more difficult by the implications for the Westminster parliament. Scotland contributes 59 of the 650 MPs, of which 40 are Labour, 11 LibDem, 6 Scottish Nationalist, 1 independent and only 1 Conservative.

So how would the markets react to independence? The immediate reaction would probably be to sell sterling.  UK government bonds (gilts) would probably weaken as well. For a start, it is not clear how the debt split would be practically acheived.

Then there is the banking sector. Some of Britain’s biggest banks are Scottish-based. Will English depositors be happy to hold their money in a foreign bank (the Icelandic example is not a good one)? Mr David Owen thinks that some banks will quickly move their domicile to London.

Detroit is the largest city ever to seek bankruptcy protection, so its bankruptcy is seen as a potential model for other American cities now teetering on the edge.  But Detroit is really a model for how wealthier and whiter Americans escape the costs of public goods they’d otherwise share with poorer and darker Americans.

Judge Steven W. Rhodes of the U.S. Bankruptcy Court for the Eastern District of Michigan is now weighing Detroit’s plan to shed $7 billion of its debts and restore some $1.5 billion of city services by requiring various groups of creditors to make sacrifices.  Among those being asked to sacrifice are Detroit’s former city employees, now dependent on pensions and healthcare benefits the city years before agreed to pay. Also investors who bought $1.4 billion worth of bonds the city issued in 2005.

Both groups claim the plan unfairly burdens them. Under it, the 2005 investors emerge with little or nothing, and Detroit’s retirees have their pensions cut 4.5 percent, lose some health benefits, and do without cost-of-living increases.

No one knows whether Judge Rhodes will accept or reject the plan. But one thing is for certain. A very large and prosperous group close by won’t sacrifice a cent: They’re the mostly-white citizens of neighboring Oakland County.  Oakland County is the fourth wealthiest county in the United States, of counties with a million or more residents.

In fact, Greater Detroit, including its suburbs, ranks among the top financial centers, top four centers of high technology employment, and second largest source of engineering and architectural talent in America.

The median household in the County earned over $65,000 last year. The median household in Birmingham, Michigan, just across Detroit’s border, earned more than $94,000. In nearby Bloomfield Hills, still within the Detroit metropolitan area, the median was close to $105,000.-

Detroit’s upscale suburbs also have excellent schools, rapid-response security, and resplendent parks.

Forty years ago, Detroit had a mixture of wealthy, middle class, and poor. But then its middle class and white residents began fleeing to the suburbs. Between 2000 and 2010, the city lost a quarter of its population.

By the time it declared bankruptcy, Detroit was almost entirely poor. Its median household income was $26,000. More than half of its children were impoverished.

That left it with depressed property values, abandoned neighborhoods, empty buildings, and dilapidated schools. Forty percent of its streetlights don’t work. More than half its parks closed within the last five years.

Earlier this year, monthly water bills in Detroit were running 50 percent higher than the national average, and officials began shutting off the water to 150,000 households who couldn’t pay the bills.

Buried within the bankruptcy of Detroit is a fundamental political and moral question: Who are “we,” and what are our obligations to one another?  Are Detroit, its public employees, poor residents, and bondholders the only ones who should sacrifice when “Detroit” can’t pay its bills? Or does the relevant sphere of responsibility include Detroit’s affluent suburbs — to which many of the city’s wealthier resident fled as the city declined, along with the banks that serve them?

Judge Rhodes won’t address these questions. But as Americans continue to segregate by income into places becoming either wealthier or poorer, the rest of us will have to answer questions like these.