The Economics of the Plague Year: How 1665 London Responded to Catastrophe

On June 7, 1665, Samuel Pepys walked through Drury Lane in London and saw, for the first time, houses marked with red crosses and the words “Lord Have Mercy Upon Us.” He recorded in his diary that the sight made him “ill.” By the end of that summer, he would be one of the few Londoners in positions of consequence who had not fled the city. The Lord Mayor stayed. Pepys, responsible for naval administration, stayed. The king and his court went to Oxford. The epidemic that Pepys witnessed was the last major outbreak of bubonic plague in England, and it would kill somewhere between seventy-five thousand and one hundred thousand people in London alone — roughly a fifth of the city’s population — in less than eighteen months.

The Great Plague of 1665 is usually told as a story of death and suffering, which it was. But it was also one of the most consequential natural experiments in economic history: a sudden, catastrophic, geographically concentrated reduction in population that forced rapid adjustment in labor markets, property markets, credit systems, and institutional capacity. Studying what actually happened to London’s economy during and after the plague year reveals patterns that apply to every epidemic that has followed.

Labor, Wages, and the Economics of Sudden Scarcity

The most immediate economic effect of catastrophic mortality is the one that seems paradoxical: surviving workers become more valuable. This is the lesson that everyone draws from the Black Death of 1348-1353, which killed somewhere between a third and a half of Europe’s population and produced a sustained rise in real wages for surviving laborers that persisted for generations. The reduction in labor supply relative to land and capital increases the marginal product of each surviving worker, which in competitive markets translates into higher wages.

The 1665 plague operated on a smaller scale but with the same basic mechanism. London’s skilled trades — carpenters, smiths, weavers, sailors — lost significant fractions of their membership to the disease. The parishes most severely affected were the poorer parishes of the east and south, where overcrowding, malnutrition, and proximity to the waterfront created conditions favorable to both the rats that carried fleas and the people who could not afford to leave. The parishes of Westminster and the wealthier western neighborhoods suffered less, partly because their residents had the resources to leave and partly because lower population density reduced transmission.

The result was a geographic and occupational skew in mortality that complicated the simple supply-reduction story. The laboring classes who worked in the most affected trades and neighborhoods suffered disproportionate mortality, creating genuine scarcity of unskilled and semi-skilled labor in the plague year. But the professional classes and wealthy merchants who fled to the countryside during 1665 returned in 1666 to find their businesses and properties intact. The adjustment was real but uneven, and the labor scarcity that created wage pressure for surviving workers had largely resolved within two years of the epidemic’s peak.

This speed of adjustment distinguishes the 1665 experience from the Black Death and matters enormously for understanding epidemic economics. The Black Death killed a large enough fraction of population across a wide enough geographic area to fundamentally reset the ratio of land to labor throughout Europe. The Great Plague, though devastating in human terms, killed a smaller fraction of a larger population in a smaller area, and London’s position as the primary port and commercial center of England meant that labor supply could be replenished relatively quickly through migration from less-affected regions.

Credit, Commerce, and Institutional Resilience

What is most striking about London’s economic response to the plague of 1665 is how much institutional activity continued. The port never fully closed. The Navy Office, under Pepys’s management, continued contracting for ships and supplies throughout the epidemic, adapting its operations to the departure of staff but maintaining essential functions. The bill of exchange system that financed English overseas trade continued operating, with transactions increasingly conducted through agents and correspondents in provincial towns as London merchants relocated.

This institutional resilience was not inevitable. It reflected specific prior investments in contractual and organizational infrastructure that could function with reduced personnel and through written correspondence. The development of reliable written instruments — bills of exchange, promissory notes, letters of credit — in the preceding century had created financial mechanisms that did not require face-to-face contact to function. This was adaptive: when face-to-face contact became lethal, commerce could continue through paper.

The Bank of England did not yet exist — it would be founded in 1694 — but the goldsmiths who performed banking functions in Restoration London demonstrated remarkable continuity of operation during the plague year. Their ledgers from 1665 show continued deposit-taking and lending through the epidemic, with some adjustment in the risk premium charged on loans (reflecting uncertainty about counterparty survival) but no collapse of credit function. The informal institution of goldsmith banking was robust enough to absorb significant personnel losses while maintaining core operations.

This resilience had limits. The plague year coincided with the Second Anglo-Dutch War, and the combination of epidemic mortality, disrupted trade, and war expenditure created serious fiscal pressure on the Crown. Charles II’s government was already heavily indebted, and the plague’s disruption of trade reduced customs revenues precisely when military expenditure was rising. The fiscal crisis that culminated in the Stop of the Exchequer in 1672 — effectively a sovereign default that destroyed the savings of the goldsmith depositors who had lent to the Crown — was not caused by the plague, but the plague materially worsened the fiscal trajectory that led there.

Property Markets and the Logic of Contagion Risk

The geography of plague mortality in 1665 London created a natural experiment in how property markets price contagion risk. The most affected parishes — St. Giles in the Fields, Stepney, Whitechapel — saw not only devastating mortality but rapid shifts in property occupation as surviving residents fled and returning residents avoided areas with recent high death rates.

Contemporary accounts describe houses standing empty in the most affected parishes for months after the peak of mortality. This is consistent with what economists would expect: the combination of real mortality risk and psychological avoidance of recently contaminated spaces creates a demand collapse in affected areas that takes time to reverse. The mechanism is partly rational — avoiding areas where plague persisted longer — and partly irrational — avoiding areas where plague had already passed because of stigma or psychological association.

Property values in the most affected parishes recovered relatively quickly by the standards of modern disease-affected real estate, for the simple reason that the epidemic demonstrated conclusively its own limits. When the plague subsided in the winter of 1665-1666, it subsided completely — it did not smolder and resurge for years as some epidemics do. The return of evacuated residents and the reoccupation of empty properties proceeded rapidly, and the Great Fire of September 1666, which destroyed much of the old city, effectively reset property values in the burned area regardless of plague history.

The interaction between the plague of 1665 and the Fire of 1666 is one of the more remarkable sequences in urban economic history. The plague cleared a substantial fraction of London’s population from densely built wooden housing. The fire destroyed much of that housing within the following year. The rebuilding that followed under the direction of Christopher Wren and Robert Hooke produced a city with wider streets, stone construction, and lower residential density in the old city — changes that were economically costly in the short term but substantially reduced both fire risk and, though contemporaries did not understand the mechanism, plague transmission. The catastrophe created the political conditions for the urban reforms that had been resisted for decades before it.

Public Health Administration and the Limits of Early Modern Response

The official response to the 1665 plague reflected the extent and limits of early modern epidemiological understanding. The Bills of Mortality — weekly published counts of deaths by parish and cause — provided a surveillance system of remarkable sophistication for the period. London had maintained this system since the sixteenth century, and while the attribution of cause of death was often inaccurate, the geographic and temporal tracking of mortality allowed officials to monitor the epidemic’s progress and make at least rough assessments of its severity.

The interventions available were quarantine and isolation — households where plague was identified were locked and guarded, the red cross painted on the door, the inhabitants confined for forty days. The effectiveness of this measure is contested: household quarantine may have concentrated transmission within families while reducing spread to neighbors, with ambiguous aggregate effects. What is not contested is that it was deeply unpopular and widely evaded. Contemporary accounts describe extensive bribery of watchmen assigned to sealed houses, nighttime escapes, and concealment of deaths to avoid confinement.

The public health administration of 1665 London also illustrates the persistent tension between economic and health interests in epidemic response. The city’s merchants and guild masters consistently argued against measures that would disrupt commerce, and the actual imposition of restrictions was considerably weaker in commercial areas and on commercial activities than the official regulations specified. Pepys records continued commercial activity throughout the epidemic in ways that the formal restrictions theoretically prohibited. The gaps between official policy and actual enforcement reflected not incompetence but the same political economy that has characterized epidemic response ever since: those who bore the economic cost of restrictions were better represented in decision-making than those who bore the health cost of inadequate restrictions.

What 1665 Teaches About Epidemic Economics

The Great Plague of 1665 killed approximately seventy-five thousand to one hundred thousand people in London in less than a year and a half. London’s population in 1670 was roughly the same as in 1664. This recovery happened through a combination of natural increase, which was rapid given the young age structure of the pre-plague population, and migration from provincial England attracted by higher wages and expanded economic opportunities in a city that had just experienced massive labor scarcity.

The speed of demographic recovery, combined with the institutional resilience of London’s financial and commercial infrastructure, produced an economic history in which the Great Plague appears as a terrible interruption rather than a permanent discontinuity. This is the correct interpretation, but it requires understanding why some catastrophes produce permanent discontinuities and others do not.

The key variables are the fraction of population killed, the geographic scope of mortality, the speed of demographic recovery, and crucially the robustness of institutions. London in 1665 had institutions — property law, commercial contracts, written financial instruments, a functioning municipal administration — capable of absorbing catastrophic personnel losses while maintaining core functions. Cities and societies without such institutions do not recover from comparable mortality at comparable speeds. The plague year is not simply a story of human resilience. It is a story of institutional investment producing resilience when catastrophe arrives.

The lesson is not comforting for most of the world. London’s resilience in 1665 reflected centuries of institutional development that most of the world’s population did not share and many do not share today. The epidemics that have produced genuine long-term economic damage — the influenza pandemic of 1918 in developing countries, plague in parts of Africa, cholera across South Asia through the nineteenth century — did so in places where institutional infrastructure was thinner and recovery mechanisms correspondingly weaker. The difference between an epidemic that interrupts and an epidemic that destroys is not primarily biological. It is institutional, which means it is a policy choice made decades and centuries before the pathogen arrives.