Instruct: Given a question, retrieve relevant documents that answer the question.
Query: What is the public debt of the U.S.?
As of December 31, 2018, debt held by the public was $16.1 trillion and intragovernmental holdings were $5.87 trillion, for a total or "National Debt" of $21.97 trillion.[5] Debt held by the public was approximately 76.4% of GDP in Q3 2018[6]. In 2017, the US debt-to-GDP ratio was ranked 43rd highest out of 207 countries.[7] The Congressional Budget Office forecast in April 2018 that the ratio will rise to nearly 100% by 2028, perhaps higher if current policies are extended beyond their scheduled expiration date.[8]
The ratio is higher if the total national debt is used, by adding the "intragovernmental debt" to the "debt held by the public." For example, on April 29, 2016, debt held by the public was approximately $13.84 trillion or about 76% of GDP. Intra-governmental holdings stood at $5.35 trillion, giving a combined total public debt of $19.19 trillion. U.S. GDP for the previous 12 months was approximately $18.15 trillion, for a total debt to GDP ratio of approximately 106%.[36]
Therefore, since the total U.S. public debt was approximately $11.053 trillion as of July 2012, the public debt will climb by the end of FY2013 to either $11.664 trillion. 
This table lists the U.S. federal debt as a percentage of gross domestic product, or GDP, each year since World War II. The gross federal debt shown below reached 102.7% of GDP at the end of 2012, the most recent figure available; it was the highest percentage since 1945 and the first yearly percentage figure to go over 100% since then. (The gross federal debt in the table includes intra-government debt – that is, money owed by one branch of the federal government to another. When this latter amount is subtracted, the remaining quantity is known as the public debt.)
The CBO estimated under the baseline scenario that the U.S. debt held by the public would increase approximately $8.5 trillion between the end of 2014 and 2024. Under a $2 trillion deficit reduction scenario during that first decade, federal debt held by the public in 2039 would stand at 75 percent of GDP, only slightly above the value of 72 percent at the end of 2013. Under a $4 trillion deficit reduction scenario for that decade, federal debt held by the public would fall to 42 percent of GDP in 2039. By comparison, such debt comprised 35 percent of GDP in 2007 and has averaged 39 percent of GDP during the past 40 years.[62]
U.S. household and non-profit net worth exceeded $100 trillion for the first time in Q1 2018; it has been setting records since Q4 2012. The U.S. federal government or "national debt" was $21.1 trillion in May 2018, just over 100% GDP. Using a subset of the national debt called "debt held by the public", U.S. debt was approximately 77% GDP in 2017. By this measure, the U.S. ranked 43rd highest among 2017 nations. Debt held by the public rose considerably as a result of the Great Recession and its aftermath. It is expected to continue rising as the country ages towards 100% GDP by 2028.
Public Debt’s mission is to borrow the money needed to operate the federal government, account for the resulting debt, and provide reimbursable support services to federal agencies. Financing the federal government is accomplished by selling Treasury bills, notes, bonds, Treasury inflation-protected securities, and U.S. Savings Bonds. 
If the U.S. continues to run "on budget" deficits as projected by the CBO and OMB for the foreseeable future, it will have to issue marketable Treasury bills and bonds (i.e., debt held by the public) to pay for the projected shortfall in the Social Security program. This will result in "debt held by the public" replacing "intragovernmental debt" to the extent of the Social Security Trust Fund during the period the Trust Fund is liquidated, which is expected to occur between 2015 and the mid-2030s. This replacement of intragovernmental debt with debt held by the public would not occur if: a) The U.S. runs on-budget surpluses sufficient to offset "off-budget" deficits in the Social Security program; or b) Social Security is reformed to maintain an off-budget surplus.
The U.S. Treasury statistics indicate that, at the end of 2006, non-US citizens and institutions held 44% of federal debt held by the public. , China, holding $1.26 trillion in treasury bonds, is the largest foreign financier of the U.S. public debt.
However, if the U.S. government continues to run "on budget" deficits as projected by the CBO and OMB for the foreseeable future, it will have to issue marketable Treasury bills and bonds (i.e., debt held by the public) to pay for the projected shortfall in the Social Security program. This will result in "debt held by the public" replacing "intragovernmental debt".[86][87]
Analysts were concerned that the political gridlock would extend into mid-October, when Congress and the President must agree to raise the debt ceiling to avoid the prospect of defaulting on the public debt. Following the debate over the debt ceiling in May 2013, the Treasury Department was forced to engage in extraordinary measures to fund the government. In August 2013, the Treasury informed Congress that the extraordinary measures would be insufficient starting in mid-October and further specified, in late September, that the U.S. would begin to default on its debts if a new debt ceiling was not approved by October 17. On October 2, President Obama explicitly linked the government shutdown to the debt ceiling issue, stating that he would not reopen budget negotiations until Republicans agreed to passage of a bill raising the debt limit. On October 7, the Moody's bond credit rating agency released a memo stating that it was unlikely the U.S. would risk a default on its public debt, and that the nation instead "would continue to pay interest and principal on its debt". The memo further stated that the financial situation was more serious in 2011 than the 2013 problem. However, such prioritizing of debt payments over all other needs would require that the government default on many other payment obligations, likely including a wide array of business contracts, employee salaries, social insurance benefits, and other programs. The Council on Foreign Relations said that among the payments implicated were military wages, Medicare and Social Security payments, and unemployment support.
A budget deficit refers to expenditures that exceed tax collections during a given period and require borrowing to fund the difference. The U.S. federal government has run annual deficits in 36 of the past 40 fiscal years, with surpluses from 1998–2001. Debt represents the accumulation of deficits over time. Debt held by the public, a partial measure of the U.S. national debt representing securities held by investors, rose in dollar terms each year except during the 1998–2001 surplus period. Total national debt rose in dollar terms each year from 1972–2014.
Historically, municipal debt predates corporate debt by several centuries—the early Renaissance Italian city-states borrowed money from major banking families. Borrowing by American cities dates to the nineteenth century, and records of U.S. municipal bonds indicate use around the early 1800s. Officially the first recorded municipal bond was a general obligation bond issued by the City of New York for a canal in 1812. During the 1840s, many U.S. cities were in debt, and by 1843 cities had roughly $25 million in outstanding debt. In the ensuing decades, rapid urban development demonstrated a correspondingly explosive growth in municipal debt. The debt was used to finance both urban improvements and a growing system of free public education.
The total federal debt is divided into "debt held by the public" and "intra-governmental debt." The debt held by the public refers to U.S. government securities or other obligations held by investors (e.g., bonds, bills and notes), while Social Security and other federal trust funds are part of the intra-governmental debt. As of September 30, 2012 the total debt was $16.1 trillion, with debt held by the public of $11.3 trillion and intragovernmental debt of $4.8 trillion. Debt held by the public as a percentage of GDP rose from 34.7% in 2000 to 40.3% in 2008 and 70.0% in 2012. U.S. GDP was approximately $15 trillion during 2011 and an estimated $15.6 trillion for 2012 based on activity during the first two quarters. This means the total debt is roughly the size of GDP. Economists debate the level of debt relative to GDP that signals a "red line" or dangerous level, or if any such level exists. By comparison, China's budget deficit was 1.6% of its $10 trillion GDP in 2010, with a debt to GDP ratio of 16%.
The U.S. public debt was $909 billion in 1980, an amount equal to 33% of America's gross domestic product (GDP); by 1990, that number had more than tripled to $3.2 trillion—or 56% of GDP. In 2001 the national debt was $5.7 trillion; however, the debt-to-GDP ratio remained at 1990 levels. Debt levels rose quickly in the following decade, and on January 28, 2010, the U.S. debt ceiling was raised to $14.3 trillion. Based on the 2010 United States federal budget, total national debt will grow to nearly 100% of GDP, versus a level of approximately 80% in early 2009. The White House estimates that the government's tab for servicing the debt will exceed $700 billion a year in 2019, up from $202 billion in 2009.
For information on the United States public debt divided by Gross Domestic Product by Presidential term, see National Debt by U.S. presidential terms
As of January 2012, public debt owned by foreigners has increased to approximately 50% of the total or approximately $5.0 trillion. As a result, nearly 50% of the interest payments are now leaving the country, which is different from past years when interest was paid to U.S. citizens holding the public debt. Interest expenses are projected to grow dramatically as the U.S. debt increases and interest rates rise from very low levels to more typical historical levels.
Debt sustainability is a major issue, particularly for countries facing higher public debts, such as what most advanced economies are currently experiencing. These countries are vulnerable to rollover risks as maturing debt obligations could become more expensive to refinance considering that investors will demand significant premium to compensate for the greater risks that they will be assuming. The punitive action of the market through higher borrowing costs will make it more difficult for these countries to service their obligations, creating a vicious cycle of debt trap. This could be aggravated when governments planning to undertake unpopular measures that will increase revenues and/or reduce public expenditures face political backlash that render them not politically feasible.
War debt payments by World War I Allies to the U.S. had been suspended in 1931—only Finland paid in full—and American public opinion demanded repayments resume as a condition of U.S. postwar aid. Germany had suspended its reparations payments due under the 1919 Versailles Treaty and payable to Britain, France and others, as well as loans due to the United States. Chancellor Konrad Adenauer decided that permanent good will required their resumption. The 1953 Agreement on German External Debts, which resumed German's war reparations, is a notable example of international debt relief.
On August 5, 2011, the United States debt-ceiling crisis of 2011, the credit rating agency Standard & Poor's downgraded the rating of the federal government from AAA to AA+. It was the first time the U.S. had been downgraded since it was originally given a AAA rating on its debt by Moody's in 1917. BBC News reported that Standard & Poor's had "lost confidence" in the ability of the U.S. government to make decisions.
U.S. official gold reserves as of 31July2014 total 261.5 million troy ounces with a book value of approximately $11.04 billion.[119] Foreign exchange reserves $140 billion as of September2014.[120] The national debt equates to $59,143 per person U.S. population, or $159,759 per member of the U.S. working taxpayers, as of March 2016.[121] In 2008, $242billion was spent on interest payments servicing the debt, out of a total tax revenue of $2.5trillion, or 9.6%. Including non-cash interest accrued primarily for Social Security, interest was $454billion or 18% of tax revenue.[108] Total U.S. household debt, including mortgage loan and consumer debt, was $11.4trillion in 2005. By comparison, total U.S. household assets, including real estate, equipment, and financial instruments such as mutual funds, was $62.5trillion in 2005.[122] Total U.S. Consumer Credit Card revolving credit was $931.0billion in April 2009.[123] The U.S. balance of trade deficit in goods and services was $725.8billion in 2005.[124] According to the U.S. Department of Treasury Preliminary 2014 Annual Report on U.S. Holdings of Foreign Securities, the United States valued its foreign treasury securities portfolio at $2.7 trillion. The largest debtors are Canada, the United Kingdom, Cayman Islands, and Australia, whom account for $1.2 trillion of sovereign debt owed to residents of the U.S.[125] The entire public debt in 1998 was attributable to the cost of research, development, and deployment of U.S. nuclear weapons and nuclear weapons-related programs during the Cold War.[126][127][128]
Public debt owned by foreigners has increased to approximately 50% of the total or approximately $3.4 trillion. As a result, nearly 50% of the interest payments are now leaving the country, which is different from past years when interest was paid to U.S. citizens holding the public debt. Interest expenses are projected to grow dramatically as the U.S. debt increases and interest rates rise from very low levels in 2009 to more typical historical levels. CBO estimates that nearly half of the debt increases over the 2009–2019 period will be due to interest.
According to the CIA World Factbook, during 2015, the U.S. debt to GDP ratio of 73.6% was the 39th highest in the world. This was measured using "debt held by the public."[34] However, $1 trillion in additional borrowing since the end of FY 2015 has raised the ratio to 76.2% as of April 2016 [See Appendix#National debt for selected years]. Also, this number excludes state and local debt. According to the OECD, general government gross debt (federal, state, and local) in the United States in the fourth quarter of 2015 was $22.5 trillion (125% of GDP); subtracting out $5.25 trillion for intergovernmental federal debt to count only federal "debt held by the public" gives 96% of GDP.[35]
The United States is the largest importer of goods and second-largest exporter, though exports per capita are relatively low. In 2010, the total U.S. trade deficit was $635 billion. Canada, China, Mexico, Japan, and Germany are its top trading partners. In 2010, oil was the largest import commodity, while transportation equipment was the country's largest export. Japan is the largest foreign holder of U.S. public debt. The largest holder of the U.S. debt are American entities, including federal government accounts and the Federal Reserve, who hold the majority of the debt.
In 1939, Congress instituted the first limit on total accumulated debt over all kinds of instruments. The debt ceiling, in which an aggregate limit is applied to nearly all federal debt, was substantially established by Public Debt Acts passed in 1939 and 1941 and subsequently amended. The United States Public Debt Act of 1939 eliminated separate limits on different types of debt. The Public Debt Act of 1941 raised the aggregate debt limit on all obligations to $65 billion, and consolidated nearly all federal borrowing under the U.S. Treasury and eliminated the tax-exemption of interest and profit on government debt.