The Psychology of Spending Someone Else’s Money

People behave differently when they are spending someone else’s money.

Not deliberately and not irresponsibly, but differently.

The same person who compares prices carefully when buying something for themselves might make a faster decision at work. They might choose convenience over cost, speed over process, or familiarity over policy.

It is not a lack of discipline; it is human nature.

And in most organizations, it shows up quietly in day-to-day spending decisions.

Why the Rules Change at Work

When people spend their own money, there is a direct connection between the decision and the consequence.

At work, that connection is less visible.

The money comes from a budget, not a personal account. The impact is spread across a department or the wider organisation. And in many cases, the feedback loop is slow or non-existent.

That changes how decisions are made.

Research in behavioural economics has shown that people are less price-sensitive when spending money that is not their own. The “principal-agent problem” highlights how decision-makers do not always bear the full cost of their choices, which can lead to less careful spending behaviour (NBER, n.d.).

This is not surprising. Without a clear sense of ownership, spending feels different.

Small Decisions Add Up

Most organizations do not lose control through one large purchase.

It happens through hundreds of smaller decisions.

A slightly more expensive supplier because it is easier. A quicker purchase that skips part of the process. A renewal that is approved without much scrutiny.

Individually, these decisions seem reasonable.

Collectively, they create a pattern.

Inefficiencies in procurement and purchasing processes can account for a significant percentage of operational waste, particularly in decentralized organizations where oversight is limited (World Bank, 2020).

Manual purchasing and invoice processes can also increase costs by up to 20 percent due to errors, duplication, and lack of control (IOFM, 2019).

The common thread is not intent. It is behaviour shaped by the environment.

Visibility Changes Behaviour

One of the most effective ways to influence spending behaviour is not stricter rules.

It is better visibility.

When people can see the impact of their decisions in real time, behaviour starts to shift. When budget holders know what has already been committed, they make different choices. When approvals are visible and traceable, decisions carry more weight.

Transparency in financial decision-making has been shown to increase accountability and lead to more considered spending behaviour (Harvard Business School, n.d.).

It is not about restricting people. It is about giving them the context to make better decisions.

Why Policies Alone Don’t Work

Most organizations already have policies in place, whether that’s in the guise of preferred suppliers, approval limits, or expense guidelines.

The issue is not the absence of rules. It is how easy they are to follow.

If the process is slow or difficult, people find workarounds. They use familiar suppliers, bypass systems, or deal with approvals later.

Over time, those workarounds become normal.

And once that happens, the policy still exists, but it is no longer shaping behaviour.

Where Process Makes the Difference

If behaviour is shaped by the environment, then process becomes critical.

The way purchasing is set up influences how decisions are made.

When the process is disconnected, with approvals happening after the fact and limited visibility at the point of purchase, it is much harder to guide behaviour.

When the process is structured, with clear approval steps, real-time visibility, and access to approved suppliers, the same people make different decisions.

Not because they are being forced to, but because the process supports it.

From Control to Influence

This is where the conversation starts to change.

Instead of trying to control spend after it happens, organizations begin to influence how decisions are made in the first place.

They provide visibility at the right time. They make the preferred option the easiest one. They ensure approvals are part of the process, not an afterthought.

This does not slow things down; in many cases it removes friction because the right path is clearer.

The Bigger Picture

Spending behaviour is not just a finance issue.

It reflects how people interact with systems, processes, and information.

When those elements are aligned, better decisions happen naturally.

When they are not, even the best policies struggle to have an impact.

Understanding the psychology behind spending is a useful starting point.

Because once you recognize that behaviour is shaped by the process, not just the person, it becomes much easier to improve it.

References

National Bureau of Economic Research (NBER) (n.d.) Principal-agent problems and consumer behaviour. Available at: https://www.nber.org (Accessed: 27 April 2026).

World Bank (2020) Public procurement and value for money. Washington, DC: World Bank. Available at: https://www.worldbank.org (Accessed: 27 April 2026).

Institute of Finance & Management (IOFM) (2019) The cost of manual accounts payable processes. Available at: https://www.iofm.com (Accessed: 27 April 2026).

Harvard Business School (n.d.) Transparency and accountability in financial decision-making. Available at: https://www.hbs.edu (Accessed: 27 April 2026).