Infrastructure spending is spending on transportation, power, and water facilities are public goods that benefit everyone in the economy. Government provision of these goods is critical to the economy, and this type of spending does have a stimulatory effect on gross domestic product (GDP).

This impact of government spending on infrastructure can be larger than some other types of spending. However, its effectiveness as a stimulus isn’t always straightforward or guaranteed. In practice, transportation spending is effective in specific circumstances.

Infrastructure projects are appealing to politicians as a form of fiscal stimulus. The sprawling construction sites that infrastructure spending creates are a visible reminder to voters that the government is working to address a crisis. They are often touted as excellent methods of fiscal stimulus, irrespective of the benefits of the end products that they produce.

This means that concerned citizens need to be aware of the strengths and weaknesses of infrastructure as a form of stimulus because politicians may default to it due to its power as a political signal.

It’s also important to remember that the question is not whether infrastructure spending boosts the economy, but whether it does so better than alternative forms of fiscal stimulus. Policymakers must weigh the positive outcomes of one project against another when setting the budget to complete the work.

Learn more about when infrastructure spending is most effective as a form of economic stimulus.

Theory of Infrastructure Stimulus

The idea of infrastructure spending as an economic stimulus is rooted in Keynesian economics. In Keynesian theory, when a recession happens, the economy can get stuck with sustained high unemployment and a stagnant GDP for an extended period due to a deficiency of aggregate demand. When consumers and businesses buy less stuff, businesses lose sales and fire workers, those workers buy less, and the cycle continues in a self-sustaining manner.1

According to the Keynesians, one option to deal with this situation is for the government to directly make up for the lack of private sector demand by replacing it with demand from the public sector financed by deficit spending. In the broadest sense, this spending can really be on anything.

Keynes created a thought experiment to prove his point that, if unemployment were extreme enough, it would be a useful stimulus to the economy to simply bury bottles of money in a coal mine and let people dig them up.

While this is often misinterpreted as a literal suggestion, it was meant to show that any form of fiscal stimulus could have a positive effect on closing the output gap in the economy. As Keynes himself said, “It would, indeed, be more sensible to build houses and the like.”1

Multiplier Effect

How effective stimulus is at closing the output gap depends on the multiplier effect. The multiplier effect is a name for the fact that every dollar of government spending creates some additional amount of private sector spending. For example, the government hires a person to build a road, that person goes out and spends money at a store, the owner of which hires more workers with the money, and so on.1

The size of this effect depends on where those dollars are spent. If dollars are given to people who are going to save them, then the multiplier effect will be small, but if the government gives those dollars to people who will spend them—allowing them to flow into the economy—then the multiplier will be larger.

This can allow a fiscal stimulus to have a significantly larger effect on the economy than just the number of dollars spent by the government, allowing the economy to be brought out of recession while minimizing deficit spending.1

Economic Impact of Infrastructure Stimulus

Recent estimates by the Congressional Budget Office (CBO) and a meta-analysis of empirical results from economic research suggest that public investment spending does lead to a stimulating effect on private spending components of GDP and has a larger impact on GDP via the multiplier effect than other types of spending. On paper, then, the aggregate effect of infrastructure spending would seem like an appealing option for fiscal stimulus.23

However, if reversing the effects of a negative economic shock by stimulating the economy is the goal, then proponents of economic stimulus generally agree on three principles of what stimulus spending should look like beyond just the sheer size of the multiplier under the best circumstances.

While empirical research suggests that infrastructure spending may have a strong multiplier effect overall under the best conditions, meeting these three criteria may be a challenge.

Timely

To stop an economy’s rapid downward spiral, stimulus spending must get into the economy quickly. Spending programs that take months or years to complete may take too long to have a timely impact. Delays in spending not only might reduce the impact on a current economic crisis but also might be counterproductive if they come too late and contribute to overheating the economy.

Targeted

To stimulate the economy, spending needs to get into the hands of people who will spend it quickly to multiply its impact. Usually, this means lower-income households and people who are most economically distressed by the downturn. Recipients who save the money or use it to pay down existing debt can defeat the purpose of stimulating new spending, and the multiplier effect of the stimulus drops.

Temporary

Stimulus spending needs to be limited to when it is needed to deal with a recession. Otherwise, permanent increases in deficit spending can lead to unsustainable government debt, crowd out private investment spending, or create undesirable microeconomic distortions in the economy.4

Special Considerations

Infrastructure construction projects may take a few quarters or a few years to even get off the ground due to implementation lag. This means that the stimulus may not be timely, regardless of its total impact.

Construction spending tends to peak years after a project is started, by which time the economy is often already recovering. This can create a pro-cyclical pattern, where the spending is held up during the time when the economy is suffering and then later overstimulates the economy during times when it isn’t needed.

In this case, the large multiplier effect associated with this kind of spending can be counterproductive, exaggerating rather than smoothing out economic cycles. While there may be infrastructure projects ready to be fully funded at the time of the crisis, there are only a limited number of those. This means that there are only so many infrastructure projects that would be useful as a stimulus.5

Because infrastructure spending is usually for a specific budgeted amount to fund specific projects, on its face, it does tend to meet the criterion of being temporary; however, cost overruns and other issues can drag this out. One caveat is that infrastructure strongly influences regional economic development patterns.

Risks of Infrastructure Spending for Economic Stimulus

If infrastructure is built solely for the purpose of providing economic stimulus, not because it provides changes to regional economic development that we want, it could cause significant negative long-term effects.

This is doubly important to remember as infrastructure might be rushed to provide timely stimulus in a way that doesn’t consider longer-term implications. This further limits infrastructure stimulus to projects that are already significantly developed.

Finally, targeting infrastructure spending effectively to meet macroeconomic goals can be problematic. Such spending tends to inevitably target the heavy construction industry, which may or may not be particularly hard hit in any given recession.

Furthermore, investment in fixed capital, like infrastructure, is necessarily highly localized; there is no reason to expect that the regional distribution of infrastructure needs will coincide with the geographic distribution of the impact of a recession.

This can create tension between two goals: economic stimulus and actual public need for the infrastructure. Moreover, several studies have shown that in practice, the distribution of stimulus-related infrastructure spending is often heavily influenced by political and electoral considerations rather than by either of these two goals.789

While this can make infrastructure spending very appealing to policymakers and politicians, it can work counter to the economic goals of the policy.

When Infrastructure Spending Works

If infrastructure is rushed and planning stages are skipped to try and provide more timely stimulus, it could have long-lasting negative consequences to regional economies that do lasting harm well after the recession ends.

This means that to be an effective fiscal stimulus, infrastructure projects need to meet two criteria.

First, the government should provide funding for projects that are actively needed. They should be already planned or even already started. Those existing projects need to be located in regions most severely hit by the recession, which limits options even more.

Second, the recession needs to have hit industries involved in infrastructure creation, such as construction and heavy manufacturing. Otherwise, the stimulus won’t target the people who most need it.

The strong multiplier effect of infrastructure spending means that stimulus can be a powerful tool for economic growth. But these criteria mean that stimulus can only be deployed effectively in a very limited way. If these considerations are ignored, then infrastructure spending becomes an ineffective, or even counterproductive, fiscal policy tool.

The Infrastructure Investment and Jobs Act

President Biden signed the Infrastructure Investment and Jobs Act into law on Nov. 15, 2021. This $1.2 trillion infrastructure bill included more than a half-trillion dollars to rebuild roads and bridges, maintain the water infrastructure, provide faster Internet across the entire nation, and more. In addition, funds were made available for expanding renewable energy projects.10

While a large infrastructure package, the law is only around half the size of Biden’s original proposal, which also included a $1.75 trillion Build Back Better (BBB) plan that was to deal more with social and public health infrastructure. The BBB plan was significantly pared back to become the Inflation Reduction Act, signed into law on Aug. 16, 2022.1112

The Bottom Line

Transportation, power, and water facilities are public goods that are needed to ensure that a nation runs smoothly and that citizens’ basic needs are met. Infrastructure spending is often thought of as an excellent way to stimulate the economy, regardless of the outcome of the individual projects.

Infrastructure spending can stimulate broad, macroeconomic aggregates such as GDP or total employment. However, because infrastructure projects take a long time to get started, they cannot always provide stimulus in a timely manner to help during a recession. Infrastructure spending is most effective if it fulfills a need that already exists, is executed in a timely manner, and puts money into the hands of industries and workers that are impacted by a recession.