A short paper is not necessarily a small idea. It can isolate one central result and become the starting point for a broader paper with richer mechanisms, stronger identification, or more demanding inference. Our new CAMA working paper on geopolitical alignment and international financial institution lending is the latest example.
When I write a short paper, I usually try to isolate a precise question, a transparent empirical result, and one central message. The format forces difficult but useful choices: What is essential? What can be left aside? What is the minimum amount of evidence needed to establish the contribution convincingly?
A short article can therefore be a complete contribution in its own right. At the same time, it often leaves open several questions concerning the underlying mechanisms, the external validity of the results, or the strength of the identification.
For this reason, I often develop papers in families. Most commonly, a short article comes first and a longer paper later expands the idea, develops the mechanisms, or strengthens the empirical design. But the sequence can also run in the opposite direction: a broad project may reveal a precise question that deserves a shorter, more focused paper.
The larger paper should not simply be the short paper with more pages and robustness tables. It should ask a broader or more demanding question. It may extend the sample, introduce new outcomes, develop the theoretical mechanisms, improve the identification or inference, or determine where the initial result does—and does not—hold.
In fact, a successful “big brother” does not necessarily make the original finding larger or more spectacular. It may instead make it more conditional, more nuanced, and ultimately more credible.
This approach should not be confused with salami slicing. Each article must stand on its own and make a sufficiently distinct contribution. The short paper is not an incomplete version of the longer one. Rather, the two papers belong to the same research program.
Some earlier siblings
1. Fundamental equilibrium exchange rates
My first clear example concerned fundamental equilibrium exchange rates.
The short paper examined whether fundamental equilibrium exchange rates help explain long-run exchange-rate dynamics:
Saadaoui, J. (2011). “Exchange Rate Dynamics and Fundamental Equilibrium Exchange Rates.” Economics Bulletin, 31(3), 1993–2005.
A few years later, the longer paper broadened the question by placing fundamental equilibrium exchange rates within the debate over global imbalances and their correction:
Saadaoui, J. (2015). “Global Imbalances: Should We Use Fundamental Equilibrium Exchange Rates?” Economic Modelling, 47, 383–398.
The second paper therefore moved from the long-run relationship between observed and equilibrium exchange rates to the broader policy question of whether FEERs provide useful benchmarks for correcting international imbalances.
2. International reserves and US monetary tightening
A second pair started with a short paper on the stabilizing role of international reserves during the 2021–2022 US monetary-tightening cycle:
Ahmed, R., Aizenman, J., Saadaoui, J., & Uddin, G. S. (2023). “On the Effectiveness of Foreign Exchange Reserves During the 2021–22 US Monetary Tightening Cycle.” Economics Letters, 233, 111367.
Its “big brother” revisits the reserve-buffer hypothesis using identified high-frequency FOMC surprises, minute-level exchange rates, and predetermined reserve holdings for 18 economies:
Aizenman, J., Saadaoui, J., Uddin, G. S., & Yago, N. (2026). “US Monetary Spillovers, Foreign Exchange, and Gold Reserves at Times of Geopolitical Fragmentation.” NBER Working Paper No. 35337.
The larger paper decomposes reserves into dollar, non-dollar, and gold holdings. It also studies the roles of Federal Reserve swap and repo facilities and countries’ external dollar exposure. The identification is substantially strengthened by combining high-frequency monetary-policy surprises with minute-level exchange-rate responses.
3. International reserves and real-exchange-rate adjustment
The family relationship can also develop in the opposite direction. A broad paper can generate a more focused regional sibling.
The global paper studies more than 110 countries and shows that the development of financial institutions conditions the capacity of international reserves to buffer real-exchange-rate adjustment:
Aizenman, J., Ho, S. H., Huynh, L. D. T., Saadaoui, J., & Uddin, G. S. (2024). “Real Exchange Rate and International Reserves in the Era of Financial Integration.” Journal of International Money and Finance, 141, 103014.
The shorter article applies the same broad intuition to Europe and Central Asia, using a more focused regional design and panel-threshold methods:
Saadaoui, J. (2024). “Financial Development, International Reserves, and Real Exchange Rate Dynamics: Insights from the Europe and Central Asia Region.” Finance Research Letters, 70, 106359.
Here, the two papers are complementary: one establishes the general international pattern, while the other examines its relevance within a more homogeneous regional setting.
4. US partisan conflict, US–China tensions, and oil prices
A fourth pair concerns the interactions between US domestic political conflict, bilateral relations with China, and the global oil market.
The short paper isolates the scapegoating hypothesis and studies how its relevance changes over time:
Cai, Y., & Saadaoui, J. (2025). “US–China Tensions, US Partisan Conflict, and Global Oil Prices: Scapegoating?” Applied Economics Letters, article 2522908.
The longer paper embeds partisan conflict and US–China political-relation news in a more complete oil-market system. It distinguishes demand, supply, and price responses and examines asymmetries between positive and negative political news:
Cai, Y., Saadaoui, J., & Uddin, G. S. (2025). “US Partisan Conflict, Sino-US Political Relation News, and Oil Market Dynamics.” Energy Economics, 149, 108820.
The short article concentrates on one political-economy mechanism, while the longer article provides a broader representation of the interactions among domestic polarization, bilateral political relations, and the oil market.
5. Economic integration agreements and growth
A fifth pair illustrates particularly clearly how the relationship can run in the opposite direction. In this case, the broader paper came first:
Aizenman, J., Ito, H., & Saadaoui, J. (2026). “Comparative Advantage and Openness under Global Fragmentation: Lessons from the Past 65 Years.” NBER Working Paper No. 35242.
The NBER paper asks why openness has supported catch-up growth in some countries and regions, while in others it has been followed by stagnation, divergence, or only limited convergence. Using an unbalanced panel covering up to 145 economies between 1960 and 2024, it adopts a broad conception of openness. Trade intensity and formal economic integration are only part of the story. Countries’ positions in international trade networks, their commodity dependence, their geoeconomic connectivity and vulnerability, their human capital, and their institutional capacity also determine whether openness can be transformed into sustained productivity and growth gains.
One result in the broader paper raised a more focused empirical question. The coefficient on the lagged stock of Economic Integration Agreements was generally small and imprecisely estimated. But a stock variable combines long-standing agreements, recent accessions, gradual expansions, and large bloc-based integration episodes. It may therefore conceal the dynamic adjustment that follows a discrete increase in formal integration.
This question motivated the short companion paper:
Aizenman, J., Ito, H., & Saadaoui, J. (2026). “Economic Integration Agreements and Growth: Dynamic Evidence from Switching Treatments.” Available at SSRN, No. 7215682.
The short paper focuses exclusively on the dynamic growth effects of changes in Economic Integration Agreements. Using a country panel covering 1990–2023, it applies a heterogeneity-robust difference-in-differences estimator designed for multivalued and nonabsorbing treatments. This is important because economic integration does not generally follow a simple binary path in which a country enters one agreement and remains permanently treated. Countries can activate many bilateral agreement links simultaneously, deepen their integration later, or occasionally experience a decline in their exposure.
The treatment design compares the actual path followed by countries after their first change in EIA exposure with a counterfactual path in which exposure remains at its initial level. The analysis therefore replaces the broad average association between the stock of agreements and growth with a more precise question:
How does economic growth evolve after a country experiences a discrete expansion in formal economic integration?
The main result is a delayed growth response. Growth does not increase significantly during the year of the first positive change in EIA exposure, but rises by approximately three percentage points one year later. Four horizon-matched placebo estimates are individually and jointly insignificant. The result is also stable across alternative control groups, a common-switcher sample, and leave-one-switcher-out exercises. The evidence points toward delayed gains from major bloc-based integration episodes rather than an immediate increase in growth at the moment of accession.
This pair therefore illustrates another useful relationship between short and long papers. The broader study develops an encompassing interpretation of openness in a fragmented world, while the short paper extracts one empirical margin—formal economic integration—and investigates it with a more focused dynamic treatment design.
6. International lending and geopolitical alignment
The most recent example is a project written with Hugo Oriola.
Our short paper focused on exchange-rate reactions to loans approved by international organizations:
Oriola, H., & Saadaoui, J. (2025). “Exchange Rate Reaction to International Organization Loans and Geopolitical Preferences.” Economics Letters, 248, 112212.
Using a monthly panel of 153 countries between February 1993 and December 2019, the paper studied IMF and Asian Development Bank lending among elected temporary members of the United Nations Security Council. The identification exploited the quasi-random component of election to the Security Council and the timing provided by monthly data. The results showed that the exchange-rate response to international lending depended on the recipient country’s geopolitical preferences.
We have now completed its “big brother”:
Oriola, H., & Saadaoui, J. (2026). “Geopolitical Alignment and the Catalytic Effects of International Financial Institution Lending.” CAMA Working Paper 69/2026.
The new paper does not simply reproduce the Economics Letters analysis with additional tables. It develops an institution-specific framework explaining why geopolitical alignment can alter the way financial markets interpret a loan approval.
For the IMF, credibility is closely connected to conditionality and the influence of major shareholders. Alignment with the United States may therefore strengthen the credibility signal associated with a program, whereas alignment with another major power may lead investors to anticipate greater leniency.
The institutional logic is different for the Asian Development Bank. Its credibility depends less on strict conditionality and more on the continuity of regional financing. Alignment with China or Russia may consequently be interpreted as an additional financial or political backstop.
The empirical results reflect these differences. For IMF lending, the evidence that alignment with the United States is associated with more favorable currency reactions is weak and only marginally robust. Alignment with Russia is associated with less favorable reactions, but this result is also only marginally robust to cluster-robust inference; no comparable conditioning effect is found for alignment with China. For ADB lending, by contrast, alignment with China or Russia is associated with more favorable currency responses.
The larger paper therefore changes the question. Rather than asking only whether international lending generates a catalytic financial-market effect, it asks:
How does the market interpretation of an international loan depend jointly on the institutional source of the lender’s credibility and the recipient country’s geopolitical alignment?
This is precisely what a “big brother” paper should do. It preserves the initial intuition while subjecting it to broader data, richer mechanisms, additional outcomes, and more demanding inference.
Short papers as starting points
This is why I continue to enjoy writing short papers. The short format imposes discipline. It forces the authors to make the contribution visible and to explain the result without hiding it behind excessive detail.
But short papers can also be starting points. They help identify which mechanisms remain unclear, which results require stronger identification, and which extensions are sufficiently important to justify a new research project.
Sometimes the short paper survives almost unchanged inside the broader story. Sometimes its conclusions become more conditional. Both outcomes are useful. Research progresses not only when initial findings are confirmed, but also when they are refined.
The new CAMA Working Paper, written with Hugo Oriola, is available here: “Geopolitical Alignment and the Catalytic Effects of International Financial Institution Lending.”