Why cities borrow
A city that wants to rebuild a bridge, replace water pipes or build a library faces a timing problem. The asset costs a lot now and serves residents for decades. Paying the entire cost from one year’s budget would mean large tax increases or cutting other services for a year. Borrowing spreads the cost over the years in which the asset is used, which many people consider fairer, since future users help pay for something they benefit from.
The most common way for local governments to borrow is by issuing bonds. A bond is a loan from many investors rather than one lender: the city receives money now and promises to pay interest regularly and return the principal on a schedule. Investors can include individuals, mutual funds and institutions.
Basic terms
- Principal: the amount borrowed.
- Interest rate (coupon): the price of borrowing, usually paid at regular intervals.
- Maturity: when the principal must be repaid. Bonds for long-lived assets often run 20 to 30 years, though the length depends on the asset and local rules.
- Credit rating: an assessment by independent rating firms of how likely a borrower is to repay. Better ratings generally mean lower interest rates.
- Debt service: the total annual payment of principal and interest.
Two main types
General obligation bonds are backed by the city’s general ability to tax. The promise is broad: the city commits to repay using its overall revenue, and may be legally required to raise taxes if necessary. In many places, voters must approve them, and there may be legal limits on the amount of debt a city can carry.
Revenue bonds are backed by income from a specific source, such as water bills, tolls or parking fees. If that income falls short, investors typically cannot demand repayment from the general budget. This protects taxpayers more but usually means higher interest rates, and the project must be able to generate enough money to carry the debt.
There are other variants, including bonds repaid from dedicated tax streams, such as the growth in property taxes under tax increment financing. The security behind a bond largely determines its risk and its cost.
In some countries, including the United States, interest on many local government bonds is generally exempt from certain income taxes, which can lower borrowing costs. Rules differ by country and change over time, so this is a general point only.
A hypothetical example
Suppose a city issues $10 million of bonds at a 4 percent interest rate, repaid over 20 years with equal principal payments of $500,000 per year ($10,000,000 ÷ 20).
- In year 1, interest is 4% of $10,000,000, or $400,000. Total payment: $500,000 + $400,000 = $900,000.
- In year 20, the remaining balance at the start is $500,000. Interest is 4% of that, or $20,000. Total payment: $500,000 + $20,000 = $520,000.
Payments therefore decline over time under this structure. Many bonds are instead structured with level total payments, so the actual pattern depends on the deal. Over the full 20 years, the city would pay back the $10 million plus total interest of about $4.2 million, so the project costs substantially more than its sticker price. This is a simplified illustration with invented terms, not a forecast for any real city, and it ignores issuance costs and other charges.
What repayment commits a city to
Borrowing is a promise that outlasts the officials who made it. Several consequences follow:
- Reduced flexibility. Debt service is a fixed claim on the budget. If revenue drops in a downturn, the payments still come due, and other services may have to be cut first.
- Long-term obligations beyond construction. The asset still needs maintenance, and many cities underestimate this. Money borrowed to build something does not pay to keep it running.
- Limits on future borrowing. Rating agencies and legal caps may restrict how much more a city can borrow if its debt load is high.
- Matching life to loan. Sound practice is generally to repay a bond within the useful life of the asset. Borrowing for a short-lived item over a long period leaves future residents paying for something already worn out.
Risks and criticisms
Debt can be a sensible tool, but it is not neutral. Heavy borrowing can crowd out other spending, especially for cities with shrinking tax bases. Projects financed with revenue bonds sometimes earn less than forecast, and the shortfall hits investors or, if the city has made additional promises, taxpayers. Critics also point out that borrowing can make costly projects feel painless today while pushing costs onto people who had no say.
Transparency helps. Residents can look at a city’s annual financial report, the plan for each bond issue, the amount of debt compared with revenue, and independent credit assessments. Where voter approval is required, the ballot question typically describes what the money will pay for.
How it fits with other funding
Bonds are usually one component of the project financing mix, combined with grants, fees and private investment. A city may borrow to fund its share of a project so that it can qualify for a competitive grant that requires local matching funds. Bond financing also interacts with timing questions, since proceeds can be received before the work happens while repayment stretches on for decades. Neither the benefits of an asset nor a city’s ability to repay can be guaranteed, which is why careful forecasts and conservative assumptions matter.