Topic 02 — Firm-Level Results

What Happens to Firms After M&As?

Acquirers grow, targets shrink — but both become less profitable. There's no evidence that M&As create efficiency gains.

When a company acquires another, the buyer (acquirer) grows — it gains employees and operations. The company being bought (target) shrinks: it loses workers and its average pay falls.

But here's the surprising part: both companies become less profitable after the deal. The efficiency gains that M&As are often supposed to deliver don't show up in the data. If anything, deals seem to destroy value in the short-to-medium run.

Event-study estimates from equation (1) — a matched DiD with firm and year fixed effects, 4-digit NAICS × year controls, and a quartic in firm age — show parallel pre-trends for both targets and acquirers, supporting the design.

Post-event: target employment falls 8.9 log points, average payrolls fall 2.6 log points. Acquirer employment rises 18.8 log points with no payroll change. At the aggregate level (targets + acquirers pooled), employment and payrolls are roughly flat — the deal reshuffles, it doesn't create. Profit margins fall 0.7 pp for targets, 1.9 pp for acquirers; return on assets falls 3.3 pp and 1.3 pp respectively. These profitability declines are inconsistent with an efficiency or market-power channel.

Key finding: Neither acquiring nor target firms become more profitable after the deal. This rules out efficiency gains and increased market power as primary drivers of post-M&A worker outcomes.
−8.9%
Target employment (log pts)
+18.8%
Acquirer employment (log pts)
−1.9pp
Acquirer profit margins
−3.3pp
Target return on assets
Figure 2 (panels a–d) Employment, Payrolls & Profitability
log(Employment)
Employment
log(Average Payrolls)
Average Payrolls
Profit Margins
Profit Margins
Return on Assets
Return on Assets
Panels (a) log employment, (b) log average payrolls, (c) profit margins, (d) return on assets. Dashed lines = 95% CIs. Event in year 0; normalized to zero at year −1.
Topic 03 — Worker-Level Results

Worker Earnings After M&As

Target workers earn less after M&As. Acquirer workers are unaffected. The drop is driven almost entirely by those who change jobs.

We track individual workers — people who had been at their firm for at least 4 years before the deal — and follow their paychecks for years afterward.

Workers at the company being bought (target) see their annual earnings fall by about 1.2% on average. Workers at the buying company are essentially unaffected. The story for target workers gets more interesting when we split them: those who stay at the target firm see barely any change, but those who leave lose about 3.3%.

Worker-level DiD from equation (2) with worker and year fixed effects, standard errors two-way clustered at the worker × firm level. We track incumbent workers continuously employed at the matched firm for the full 4-year pre-event window. This tenure restriction closely parallels Jacobson et al. (1993).

Target workers: −1.2 log points in annual earnings (p<0.05). Acquirer workers: +0.4 log points (insignificant). Decomposing by job status: stayers at target firms show an insignificant −0.8 log points; movers from target firms show −3.3 log points (p<0.001). Job transition probability spikes 20 pp in the M&A year for target workers; acquirer workers show no change.

Key finding: The earnings decline at target firms is driven by job changers, not by wage cuts for those who stay. M&As are disruptive for incumbent workers even when aggregate firm employment stays flat.
−1.2%
Target worker earnings (overall)
−0.8%
Stayers at target (not significant)
−3.3%
Movers from target firms
+20pp
Job transition probability, year of M&A
Figure 3 Worker Earnings & Job Transitions After M&As
log(Earnings)
log(Earnings)
Job Transition
Job Transition
Panel (a): log earnings — all target and acquirer workers. Panel (b): job transition probability. Panel (c): log earnings restricted to stayers only. Navy = acquirer workers, orange = target workers.
Topic 04 — Job Transitions

Who Leaves — and What Happens to Them?

Target workers are far more likely to change jobs after an M&A. Most move to other companies (not unemployment) — and most go to firms outside the acquiring company.

In the year of the deal, target workers are 70% more likely to switch jobs than similar workers who never experienced an M&A. Most of them don't end up unemployed — they land at other companies. But here's the twist: most don't go to the acquiring firm either. About 80% move to completely unrelated companies.

Workers who move to the acquiring firm see smaller earnings losses. Those who move to unrelated companies lose more. And workers who switch to a completely different industry — about a quarter of movers — suffer the largest, most persistent losses.

We define job movers as workers who transition within the first two years post-event (t=0 or t=1). The movers sample is defined ex ante by treatment status — control workers may also move, but empirically most do not. This parallels the displacement literature (Jacobson et al. 1993; Lachowska et al. 2022).

Movers experience −3.3 log points overall (Table 4, col. 1). By destination: movers to acquirers show −1.6 log points (insignificant); movers to non-acquiring firms show −5.0 log points (p<0.001). ~80% of movers go to non-acquirers. Workers transitioning to a different industry show an additional 5.4 pp higher transition probability. The losses for movers are significantly smaller than mass-layoff literature benchmarks, consistent with a different macro context (M&As are pro-cyclical).

Key finding: 80% of target workers who leave do so to firms unrelated to the acquirer. This means earnings losses are not mechanically caused by forced reallocation to a specific acquirer — they reflect a broader disruption of the worker–firm relationship.
70pp
More likely to move jobs in M&A year
~80%
Move to non-acquiring firms
−5.0%
Earnings loss: movers to other firms
−1.6%
Earnings loss: movers to acquirer (n.s.)
Figure 4 (panels a–d) Earnings & Transitions for Workers Moving from Targets
log(Earnings) — All Movers
log(Earnings) — All Movers
Job Transition Probability
Job Transition Probability
log(Earnings) by Destination
log(Earnings) by Destination
Industry Switch Probability
Industry Switch Probability
Panels (a) log earnings for all movers, (b) job transition probability, (c) earnings split by destination (acquirer vs. other firms), (d) probability of switching to a different industry. Dashed lines = 95% CIs. Event in year 0; normalized to zero at year −1.
Topic 05 — The Destination Puzzle

Where Do Workers Go — and Why Do They Still Earn Less?

Workers who leave target firms move to bigger, more profitable companies with higher wage premiums. Yet they still earn less. The culprit: losing a valuable match with their old employer.

You'd expect workers who move to better companies to earn more. But that's not what happens. Workers leaving target firms land at firms that are larger, more profitable, and pay higher wages on average — and still end up earning less.

The explanation is a concept called a match premium: some workers and firms are simply a great fit for each other, and that fit itself has economic value. When an M&A forces a worker out, they lose that fit. Even a "better" company on paper can't fully replace what they had with their old employer.

We estimate AKM firm fixed effects (Abowd, Kramarz, Margolis 1999) and match effects following Woodcock (2015) / Lachowska et al. (2022). Employer fixed effects rise 3.2 log points post-move (Table 5, col. 1) — confirming movers go to higher-wage firms. But match effects fall 9.0 log points (col. 2), more than offsetting the firm-premium gain. Observable firm characteristics corroborate: movers' new employers have 49.9 log points higher revenue and 1.8 pp higher profit margins on average.

These results suggest AKM-type wage decompositions understate worker-specific match value, consistent with Borovičková and Shimer (2024)'s critique that exogenous mobility tests may be underpowered when match effects are important to mobility decisions.

Key finding: Firm quality goes up (+3.2 log pts employer fixed effect), but match quality collapses (−9.0 log pts). Workers are paying an invisible tax on job disruption: the loss of a productive employment relationship that took years to build.
+3.2%
Rise in employer wage premium (AKM effect)
−9.0%
Fall in match effect (worker–firm fit)
+50%
Higher revenue at destination firm (log pts)
+1.8pp
Higher profit margins at destination firm
Figure 5 (panels a–d) Firm Characteristics of Workers Moving from Targets
AKM Employer Fixed Effect
AKM Employer Fixed Effect
Match Effect
Match Effect
log(Revenue)
log(Revenue)
Profit Margins
Profit Margins
Panels (a) AKM employer fixed effect, (b) match effect, (c) log revenue, (d) profit margins. All relative to matched control workers. Dashed lines = 95% CIs. Event in year 0; normalized to zero at year −1.
Topic 06 — Heterogeneity

Who Gets Hit Hardest?

Long-tenured workers and high earners bear the brunt. Short-tenure workers recover quickly. This pattern is the key to understanding why M&As hurt some workers but not others.

Not all workers are equally hurt. Employees with 7 or more years at the company before the deal suffer earnings losses that are 4.5% larger than employees with just 4 years. The long-tenured group never fully recovers over our observation window.

Similarly, workers in the top earnings quintile at their firm lose 4.6% more than those in the bottom quintile. In other words: the longer and better an employment relationship, the more valuable it is — and the more painful it is to lose.

Triple-difference estimates from Table 6. Base group: movers with 4 years of tenure (minimum required for the sample). Interaction: Post × Treated × (7+ years tenure) = −4.5 log points (p<0.001). Job transition rates are statistically indistinguishable across tenure groups, ruling out differential selection into moving as the mechanism.

Earnings quintile heterogeneity: Post × Treated × Q5 = −4.6 log points (p<0.05) relative to Q1. Sector heterogeneity shows similar patterns across tradable and non-tradable sectors, further downweighting a product-market-power channel. Age heterogeneity shows the largest declines for workers 50+, consistent with the tenure pattern.

This heterogeneity is consistent with two broad model classes: (1) implicit contract models (Lazear 1979, Burdett & Coles 2003) where tenure-increasing wage profiles are breached by new management, and (2) firm-specific human capital / directed search models (Lazear 2009, Menzio & Shi 2011) where long matches reflect productive complementarities that are destroyed by the M&A.

Key finding: The concentration of losses among long-tenured, high-earning workers is consistent with models where wages rise with tenure (either through contracts or human capital accumulation). M&As provide an opportunity to breach these relationships — and the costs fall on the workers who had invested most in them.
0%
Earnings loss: movers with 4 yrs tenure
−4.5%
Additional loss: 7+ years tenure
−2.7%
Earnings loss: bottom earners (Q1)
−7.3%
Earnings loss: top earners (Q5)
Figure 6 Heterogeneity by Tenure and Earnings Quintile
log(Earnings) by Tenure
log(Earnings) by Tenure
log(Earnings) by Earnings Quintile
log(Earnings) by Earnings Quintile
Panel (a) log earnings by tenure group (4 years vs. 7+ years), (c) log earnings by within-firm earnings quintile (Q1 vs. Q5). Dashed lines = 95% CIs. Event in year 0; normalized to zero at year −1.
* Appendix figures (robustness checks, additional heterogeneity) available in the full paper.