Dot-Com Bubble vs Subprime Mortgage Crisis
Dot-Com Bubble and Subprime Mortgage Crisis are two Economic History & Events concepts in AP Economics that students often mix up. The dot-com bubble was the surge in internet company share prices during the late 1990s, followed by a crash when the promised profits never came. The subprime mortgage crisis was the wave of American home loan defaults that, amplified by securitization and bank leverage, set off a global financial panic. Here is how they compare side by side.
During the late 1990s investors bid up the shares of internet companies far beyond what their earnings could justify, and the Nasdaq index went on to lose roughly three quarters of its value from the peak. A share is worth the present value of the cash it is expected to pay out, so a bubble exists when the price is driven instead by the belief that someone else will pay more tomorrow. Cheap capital, real excitement about a new technology, and measures such as page views standing in for profits let firms with no earnings command enormous valuations. When the expected profits did not arrive, the belief reversed and prices fell fast. The bust destroyed wealth and cut business investment, but because the losses sat with equity holders rather than borrowed money inside banks, the recession that followed was mild compared with the housing crash a decade later.
Through the mid-2000s American lenders wrote mortgages for borrowers with weak credit, often at low starter rates that reset upward after a couple of years. Those loans were bundled into securities and sold on, so the firm that approved a loan no longer bore the loss if it went bad, a textbook moral hazard problem. Banks and other financial firms bought the securities with borrowed money, holding only a thin slice of their own capital against them. When house prices stopped rising, defaults climbed, the securities fell in value, and institutions borrowing twenty or thirty dollars for every dollar of capital found that capital wiped out. Lending froze, investment and consumption fell, aggregate demand shifted left, and the result was the deepest recession since the Great Depression.
Dot-Com Bubble vs Subprime Mortgage Crisis: Why Only One Broke the Banks
| Dot-Com Bubble | Subprime Mortgage Crisis | |
|---|---|---|
| Asset at the center | Shares in internet companies | Houses, and the mortgages written against them |
| How positions were funded | Mostly equity, with limited borrowing | Heavily borrowed, on small down payments and thin bank capital |
| Who absorbed the losses | Shareholders, who can lose only what they put in | Lenders and bondholders, who were owed more than the collateral was worth |
| What happened to banks | Largely intact, and lending continued | Losses ate through capital and lending between banks froze |
| Depth of the downturn that followed | Short and shallow | The deepest since the nineteen-thirties |
| Main channel to the wider economy | Lower business investment and lost paper wealth | Credit rationing, foreclosures and a collapse in construction |
| Policy response | Ordinary interest rate cuts | Rates near zero, bank rescues and large asset purchases |
Borrowed money is what turned one crash into a banking crisis
Both episodes started the same way, with an asset price running far ahead of any income the asset could ever produce. What differed was who owed money. Work an illustrative case. A buyer puts 5 percent down on a house priced at 300,000, so their own stake is 15,000 and the mortgage is 285,000. Prices then fall 10 percent and the house is worth 270,000. The loss is 30,000, twice what the buyer put in, and because the debt is still 285,000 the owner is 15,000 short even after selling. Now take an investor who puts the same 15,000 into internet shares without borrowing. A 10 percent fall costs 1,500. Even total failure of the company costs 15,000 and stops there, leaving no lender holding a bad claim. Multiply the first case across a whole mortgage market and the losses do not stay with the borrowers. They land on banks that had themselves borrowed in order to hold those loans. That is the mechanical reason a housing crash damaged the financial system while an equity crash of comparable size mostly did not. The general pattern of prices detaching from what an asset earns is at /glossary/economic-bubble.
The two crashes reached the rest of the economy by different routes
After the internet crash the damage traveled mainly through investment. Firms that had been building network capacity stopped, technology orders dried up, and paper wealth vanished from portfolios. Households trimmed spending, but they could still borrow, banks kept lending, and the downturn was brief. The housing episode traveled through credit itself. As mortgage losses cut into bank capital, banks stopped lending to each other, then to firms and households with no connection to housing. Construction collapsed, which matters more than it sounds because building employs many people and buys heavily from other industries. Homeowners who owed more than their house was worth could not sell in order to move for a job, and cut spending to keep up payments. Each of those channels feeds the others, which is why the second downturn ran so much deeper and the recovery took so much longer. The policy response scaled with the damage. The first was met with ordinary rate cuts. The second needed rates pushed to near zero, direct support for banks and large-scale purchases of assets, and employment still took years to recover. For where downturns sit in the wider cycle, see /macro/business-cycle.
Frequently asked questions
Why was the housing crash so much worse than the dot-com crash?
Because houses were bought with borrowed money and internet shares mostly were not. When share prices fell the losses stopped with the investors who owned them, but when house prices fell the losses passed straight to lenders and to the banks that had borrowed heavily to hold mortgage debt.
Were both of these bubbles?
Yes, both fit the definition, since prices in each case rose far above what the asset could plausibly earn and then collapsed. The useful distinction is not bubble versus not bubble but whether the bubble was inflated with equity or with debt, because only the debt-funded one takes the banking system down with it.
What is a subprime mortgage?
A home loan made to a borrower whose credit record, income documentation or debt level falls short of the standard a prime lender would require. Lenders charged a higher rate to compensate for the extra default risk, which made the loans attractive to buy and package while house prices were still rising.
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