????底特律的問題無疑有很多，其中人口的急劇減少無疑加速了這座城市破產的進程。過去十年間，底特律的人口減少了25%，對它的財政造成了毀滅性的影響。自2002年以來，由于人口銳減，底特律的稅收減少了40%，州撥款減少了50%。盡管它的支出也相應減少了，但在同一時期內只減少了15%。這種差距導致該底特律的資產負債表上出現了一個無比巨大的窟窿，自從2008年以來，這個窟窿平均每年都在1億美元左右。

????據底特律的緊急情況經理近日發布的一份報告表示：“盡管開支有所降低，但底特律市還在繼續進行超過財政收入的開支，同時還在發行長期債務。換句話說，底特律的開支超過了收入，從現金流的角度看，它顯然已經無力償還這些債務。”

????在增收方面，底特律可打的牌也很少。它不能提高稅率，因為底特律的稅律已經達到了密歇根州規定的法定極限；同時它也無法從密歇根州政府那里獲得額外的撥款，因為州政府的支出是嚴格與人口基數相關聯的。底特律或許只能像2008年以來那樣繼續向債務市場借錢，但這樣只會繼續加重該市的債務問題。

????因此，如果底特律無法創造更多的收入，就必須削減開支。但底特律已經把服務開支削減到了一個危險的低水平，它意味著如果進一步采取緊縮措施，也很難使各種指標向好。因此底特律需要削減它的還債支出，這項支出目前已經占到了該市預算的42%。這也就是為什么底特律的緊急情況經理凱文?奧爾決定讓這座城市破產。因為他無法與底特律的債權人們達成協議，讓該市的還債開支下降到一個底特律能夠維持的水平。

????不過與哈里斯堡或伯明罕等地不同的是，底特律發行的債務規模其實是可控的。底特律的債務總額大約有180億到200億美元，其中只有6.75億美元是所謂的一般責任債券。這是一種昂貴的債務，投資者每年的收益高達10%。對于市政債券來說，它的利率高到了荒唐的地步，但它也不是導致城市最終破產的原因。

????最終縛住了這座城市的手腳的是預計高達150億美元的各種福利支出，也就是這座城市應該付給退休工人的錢。這150億美元代表了底特律要用來支付養老金、醫療保健費用和其它退休福利開支的現值。

????因為一個愚蠢的錯誤導致破產是一回事——比如在一個垃圾焚燒項目上投入太多的金錢。但是因為滾雪球式的福利支出增長導致城市破產就完全是另一回事了。底特律的問題是結構性的，所以它需要一次徹底的手術。不幸的是，這座城市直到最后一刻才開始直面這個問題。而在此之前，它選擇了削減城市服務和增稅這種挖東墻補西墻的策略，導致人口大批外流，情況不斷惡化。警務開支的減少使底特律的犯罪率飆升到全美其它大城市的五倍，與此同時，它的人均稅務負擔也是全密歇根州最高的。這樣一來，誰還愿意住在那里？

????But of all of Detroit's issues, and there are clearly many, it is the sharp and relentless decrease in its population that appears to have hastened the city's trip to bankruptcy court. Detroit's population declined by 25% in the last decade, which has had a devastating impact on the city's finances. Since 2002, Detroit has experienced a 40% decrease in tax receipts and a 50% decrease in state funding because of this population drop. And while the city's expenses have also declined, they are down just 15% during the same time period. This disparity created a huge hole in the city's balance sheet, which has averaged around $100 million annually since 2008.

????"The City of Detroit continues to incur expenditures in excess of revenues despite cost reductions and proceeds from long‐term debt issuances," according to a recent eport on the state of the city's finances issued by Detroit's state-appointed Emergency Manager. "In other words, Detroit spends more than it takes in -- it is clearly insolvent on a cash flow basis."

????Detroit has little in the way of options when it comes to raising additional revenue. It can't jack up city tax rates, as they are already at the state-mandated legal limit, nor can it receive additional cash from Lansing, as state payouts are strictly linked to population size. Detroit could have turned to the debt markets as it has since 2008, but that would have just compounded the city's debt problems.

????So if the city can't raise more revenue, it must cut its expenses. But Detroit has already cut services to dangerously low levels, meaning that further austerity measures would barely move the needle. Detroit therefore needs to reduce its liability payments, which currently consume around 42% of the city's budget. This is the primary reason why Kevyn Orr, the city's "Emergency Manager" put the city into bankruptcy. He was unable to secure deals with Detroit's creditors that would have brought the city's debt payments down to a level that the city could handle.

????But unlike Harrisburg or Birmingham, the debt Detroit issued is manageable. Indeed, only $675 million of the city's estimated $18 to $20 billion debt load is actually linked to general obligation (GO) bonds. It is expensive debt, yielding some 10% per year for investors, which is absurdly high for a muni bond, but it isn't what is drowning the city.

????What has Detroit wrapped in chains is the estimated $15 billion in entitlement payouts the city owes its retired city workers. That number represents the present value of what it will cost the city to pay pension, health care and other retirement benefits it has promised its former city workers.

????It is one thing to fall into bankruptcy because of a stupid mistake, like spending too much on a trash incinerator project, but it is another thing entirely to be in bankruptcy because of ballooning entitlement expenses. Detroit's problems are structural, so they require radical surgery. Unfortunately, the city waited till the very last possible moment to address this issue. It chose to slash city services and jack up taxes instead, which led to increased migration, thus making the situation even worse. The cuts in police coverage mean that Detroit has a violent crime rate that is five times the national average for large cities. Meanwhile its taxes on a per capita basis are the highest of all Michigan cities. Would you live there?