📈 economics

Strategic Inertia and Institutional Change:A Behavioral Model of Price Reforms versus Action Deletion

This paper introduces a behavioral model demonstrating that while taxing inefficient default actions often fails to overcome status-quo bias due to a critical threshold, completely banning those actions guarantees a transition to superior equilibria and higher welfare, supporting the policy principle that deletion is sometimes more effective than price-based reforms.

Original authors: Madjid Eshaghi Gordji, Mohammadali Berahman, Hasti Eshaghi

Published 2026-05-22

📖 5 min read🧠 Deep dive

CC BY 4.0

Original authors: Madjid Eshaghi Gordji, Mohammadali Berahman, Hasti Eshaghi

Original paper licensed under CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

Imagine you are in a room with a friend, and you both have to choose between two chairs: a Comfy Old Chair (the status quo) and a New, Better Chair (the superior alternative).

The problem? Even though the New Chair is objectively better for both of you, you both keep sitting in the Comfy Old Chair. Why? Because moving feels like a hassle. Maybe you're worried about tripping, or you just feel psychologically attached to the old chair. In the paper, this "hassle" is called a switching cost.

The authors of this paper ask a big question: How do we get people to move to the better chair? They compare two main strategies:

The "Tax" Strategy (Price Reform): You put a small fee on sitting in the Comfy Old Chair. Maybe you charge $1 to sit there.
The "Ban" Strategy (Action Deletion): You physically remove the Comfy Old Chair from the room. It's gone. You can't sit in it even if you want to.

Here is what the paper discovers, explained through simple analogies:

1. The "Inertia" Problem

People are "boundedly rational." This is a fancy way of saying we aren't perfect calculators. We make mistakes, we get distracted, and we tend to stick with what we know (the default). The paper models this as "noise" in our decision-making. Even if the New Chair is better, the "hassle" of moving (the switching cost) keeps us stuck in the old one.

2. The "Tax" Has a Blind Spot

The authors prove that if you just put a tax on the old chair, there is a tipping point.

Below the Tipping Point: If the tax is too low (say, $1), people will still mostly sit in the old chair. The "hassle" of moving is still stronger than the annoyance of the tax. The bad habit persists.
Above the Tipping Point: If the tax is high enough, people finally switch.
The Surprise: The paper finds that this "tipping point" amount doesn't actually depend on how smart or rational the people are. Whether you are a genius or a daydreamer, the tax needs to be the same size to break the habit.

The Catch: Even if you set a high tax, the old chair is still there. As long as it exists, there's a tiny chance someone might still choose it, or the group might get stuck in a "half-and-half" situation where some sit in the old chair and some in the new one.

3. The "Ban" is a Magic Wand

Now, imagine you simply delete the old chair.

The paper proves that if you remove the option entirely, everyone moves to the New Chair.
It doesn't matter how "lazy" or "irrational" the players are. It doesn't matter how high the switching cost is. If the old chair doesn't exist, the only choice is the new one.
The "Ban" forces a perfect transition that a "Tax" can never guarantee.

4. Why "Banning" is Better for Everyone

The authors show that when the New Chair is truly better for everyone (Pareto-dominant), deleting the old chair creates more happiness (welfare) than any possible tax.

A tax might get most people to switch, but it leaves a gap where some people still sit in the old chair.
A ban gets 100% of the people to the better chair.
The paper argues that sometimes, you have to "ban" the bad option, not just "tax" it, to get the best result.

Real-World Examples Mentioned in the Paper

The authors use this logic to explain three specific real-world situations:

Climate Change: We know fossil fuels are bad, but companies are "stuck" in them (switching costs). A small carbon tax might not be enough to make them switch to green energy. But a ban on selling new gas cars (like the EU's 2035 plan) removes the option entirely, forcing the switch.
Social Media: Apps use "Like" buttons that make us addicted. Putting a warning label or a time limit (a tax) often doesn't stop the addiction because the button is still there. But if you delete the button (hide the like counts), you remove the option to get that dopamine hit, forcing a change in behavior.
International Sanctions: Putting a tariff on imports (a tax) might not stop a country from trading if they are stubborn. But a complete embargo (a ban) removes the ability to trade entirely, forcing a different outcome.

The Bottom Line

The paper's main lesson is simple: Sometimes, you can't just make the bad thing expensive; you have to make it impossible.

If you want to break a bad habit or fix a broken system, a small nudge (tax) might not work because people are too stuck in their ways. But if you remove the bad option entirely (ban), you force everyone to do the right thing, no matter how stubborn they are.

Technical Summary: Strategic Inertia and Institutional Change

Problem Statement
The paper addresses a fundamental question in economics and institutional design: why do inefficient practices, technologies, or institutions persist even when superior alternatives are available? While existing literature identifies coordination failures, path dependence, and status quo bias as causes, there is a lack of a unified framework that simultaneously incorporates (i) noisy, boundedly rational decision-making, (ii) a microfounded status quo bias (switching costs), and (iii) the possibility of altering the set of feasible actions (not just payoffs). The authors seek to determine whether policymakers can dislodge an inefficient status quo solely through price-based reforms (taxes) or if they must resort to action-deletion interventions (bans).

Methodology
The authors develop a Quantal Response Equilibrium with Status-Quo Bias (QRE-SB) within a symmetric $2 \times 2$ coordination game.

Game Structure: Two players choose between actions $X$ (the inherited default/status quo) and $Y$ (the superior alternative). Payoffs satisfy $a > c$ and $b > d$ (self-reinforcing actions) with $b > a$ (making $(Y, Y)$ Pareto-superior).
Behavioral Assumptions:
- Bounded Rationality: Players do not perfectly best-respond but follow a logit rule with precision parameter $\beta$ .
- Status Quo Bias: A fixed switching cost $\kappa \geq 0$ is incurred whenever a player deviates from the default action $X$ . This cost reduces the effective payoff of $Y$ .
Policy Interventions: The model compares two interventions:
1. Price-only Reform (Tax): A unit tax $t$ is imposed on action $X$ , shifting the payoff difference smoothly.
2. Action Deletion (Ban): Action $X$ is removed from the feasible set entirely.
Analytical Approach: The authors derive the equilibrium condition as a fixed point of a continuous function. They establish existence and uniqueness under a contraction condition ( $\beta(\alpha + \gamma) < 4$ ) and perform comparative statics on the tax threshold and welfare outcomes.

Key Contributions and Results
The paper derives three primary theoretical results:

Existence of a Tax Threshold: For any positive switching cost and any level of rationality, there exists a critical tax threshold $\bar{t} = \kappa - \frac{\alpha + \gamma}{2}$ (where $\alpha = b-c$ and $\gamma = a-d$ ).
- If the tax $t < \bar{t}$ , the status quo ( $X$ ) persists with a probability greater than 0.5.
- If $t > \bar{t}$ , the transition to the superior equilibrium ( $Y$ ) occurs with probability greater than 0.5.
- Crucial Finding: This threshold $\bar{t}$ is independent of the degree of bounded rationality ( $\beta$ ). Bounded rationality affects the slope of the response curve but not the location of the equal-probability point.
Effectiveness of Deletion: Deleting the default action $X$ forces the unique equilibrium to the superior action $Y$ with probability 1. This outcome holds regardless of the magnitude of switching costs ( $\kappa$ ) or the level of rationality ( $\beta$ ). Unlike taxation, which shifts probabilities continuously, deletion introduces a discrete change that eliminates inertia entirely.
Welfare Superiority of Deletion: When the superior equilibrium is Pareto-dominant, action deletion yields strictly higher expected welfare than any finite tax that leaves the old action feasible.
- The welfare function $W(p)$ is strictly decreasing in the probability of playing the status quo ( $p$ ).
- Since any finite tax results in $p > 0$ , the welfare under deletion ( $p=0$ ) strictly dominates the welfare under any finite tax.
- A tax can only replicate the outcome of deletion in the limiting case where $t \to \infty$ , which is practically equivalent to a ban.

Significance and Claims
The paper claims to provide a formal game-theoretic foundation for the policy intuition that "sometimes you must ban, not just tax."

Mechanism: The core mechanism is that taxes shift payoff differences smoothly, allowing inertia (switching costs) to maintain the status quo below a certain threshold. In contrast, deletion alters the feasible set, removing the strategic support for the inefficient equilibrium entirely.
Applications: The authors explicitly connect these findings to:
- Climate Policy: Suggesting that while carbon taxes are theoretically efficient, strong switching costs (e.g., infrastructure lock-in) may require bans (e.g., phasing out internal combustion engines) to ensure transition.
- Social Media Regulation: Arguing that removing addictive design features (e.g., "like" buttons) is more effective than merely taxing or warning about them.
- International Sanctions: Proposing that complete embargoes (action deletion) may be more effective than tariffs (price reforms) when the target state exhibits high inertia.
Theoretical Integration: The work bridges bounded rationality (McKelvey and Palfrey), behavioral economics (status quo bias/switching costs), and institutional change, offering a rigorous basis for the "nudge vs. shove" debate in public policy.

Limitations and Future Directions
The authors note that the current model is static and assumes symmetric payoffs. Future research directions identified include generalizing to asymmetric payoffs, $n$ -player games with network effects, introducing dynamic adjustment processes to study transition speeds and hysteresis, and endogenizing switching costs. The paper relies on numerical simulations to illustrate theoretical predictions but does not present new empirical data or laboratory experiments.