Shishim Ribo in New York City and Brooklyn
New York supplies several very large numbers: the population of the five boroughs, the population of Brooklyn, people who enter for work, and tens of millions of visitors over the course of a year. Those numbers cannot simply be placed next to the figure of shishim ribo, six hundred thousand, as though they all answer the same halachic question.
One approach asks how many people live in the city. Another asks how many people are ordinarily present in the streets of the city. Another includes people entering the city each day. A more literal road-based calculation asks whether six hundred thousand people pass through the particular road under discussion. The same New York statistic can therefore be decisive for one calculation and irrelevant to another.
The general meanings of shishim ribo belong to the broader discussion of what the six hundred thousand requirement means. Here the question is narrower: what do the actual New York and Brooklyn numbers show when each calculation is applied on its own terms?
New York City and Brooklyn are not the same statistical unit
Modern government statistics use “New York City” for the five boroughs together. The U.S. Census Bureau estimated the population of New York City at 8,584,629 on July 1, 2025.
Brooklyn must be counted separately when the halachic analysis treats Brooklyn separately. For borough-wide population figures, the corresponding Census geography is Kings County. The Census Bureau estimated the population of Kings County at 2,653,963 on July 1, 2025. Its 2020 land area is listed as 69.38 square statute miles.
That distinction matters in Rav Moshe Feinstein's own treatment of Brooklyn. In Igros Moshe, Orach Chaim IV:88, he discusses whether Brooklyn itself contains the relevant population. When extending a geometrical area would bring part of Manhattan into the calculation, he keeps the two boroughs separate because of the river between them.
A five-borough population total can establish the population of New York City as a whole. It cannot be silently substituted for the population of Brooklyn.
Rav Moshe did not use one single six hundred thousand calculation
In Igros Moshe, Orach Chaim I:139, Rav Moshe distinguishes a road outside a city from the streets of a city. For a road, his reading requires six hundred thousand to pass through that road. For a city, he argues that the number may be measured across the city rather than through each individual street.
He also writes:
“It seems reasonable that even a city which does not have six hundred thousand residents, but together with those who enter it every day has six hundred thousand, is likewise a reshus harabim. What difference is there?”
That already makes the factual inquiry broader than a resident census alone. A city may have fewer than six hundred thousand permanent residents and nevertheless reach the number when daily entrants are included.
In Orach Chaim IV:87, dated 15 Shevat 5738, January 23, 1978, Rav Moshe develops the city calculation further. He writes that the relevant estimate is how many people are found in the streets of the whole city. He frames the comparison within an area of twelve mil by twelve mil, corresponding to the dimensions he derives from the encampment in the Midbar. He then suggests, explicitly as an estimate, that perhaps one person in four or one in five is found in the streets.
This was not presented as a fixed demographic law. Rav Moshe immediately notes that cities need not all be alike. But the arithmetic shows what his estimate means. If one-fourth of the underlying population is in the streets, 2.4 million people produce 600,000 in the streets. If one-fifth is in the streets, the corresponding underlying population is 3 million.
Rav Moshe adds that people entering from other cities must also be considered. He leans toward counting those actually found outside in the streets rather than simply everyone who happens to be inside a building somewhere in the city.
The term mil in these responsa is the halachic unit used in the source. It should not be silently converted into a modern statute mile. In the following responsum Rav Moshe reports that a map supplied by the city showed Brooklyn as “twelve mil by twelve mil and a little more.” The responsum does not identify that map or give enough information about its measurement system to turn the sentence into a modern GIS calculation. The present Census land-area figure of 69.38 square statute miles is therefore useful as modern geography, not as a conversion of Rav Moshe's twelve-by-twelve-mil formulation.
The Brooklyn figures Rav Moshe used in 1979
Rav Moshe returned to the question in Orach Chaim IV:88, dated 4 Shevat 5739, February 1, 1979. He now stated that the city map had changed the factual premise on which part of the earlier discussion had rested:
“We have now learned from a map supplied by the city that all Brooklyn is only twelve mil by twelve mil and a little more. Close to three million reside there permanently, and close to a million come and go from other places for commerce, to see relatives, and for regular employment.”
He concludes from those figures that there were substantially more than six hundred thousand people in the streets for the calculation he was using.
Those numbers need to be identified accurately. The responsum identifies the city as the source of the map, but it does not identify a statistical source for the estimate of “close to three million” permanent residents or “close to a million” entrants.
The Census Bureau's later intercensal reconstruction of the 1970s gives a lower resident population for Kings County. It estimates 2,277,500 residents on July 1, 1978 and 2,242,500 on July 1, 1979. The series was issued in April 1982, so these are authoritative Census estimates for those dates, not figures that should be described as a Census table available to Rav Moshe when he wrote in February 1979. The decennial counts likewise place Brooklyn at 2,602,012 in 1970 and 2,230,936 in 1980.
The distinction is important. “Close to three million” is a population estimate stated by Rav Moshe in the responsum. It is not the Census Bureau's resident figure for Brooklyn at that time. His separate estimate of close to a million people entering for business, visits and regular work is also part of his stated factual premise, but it is not a resident population figure.
If the Census Bureau's July 1978 resident estimate is put through Rav Moshe's rough one-in-four or one-in-five illustration by itself, the results would be about 569,375 or 455,500 people in the streets. That exercise does not reproduce Rav Moshe's 1979 conclusion, because his conclusion did not use the Census resident estimate alone. He used a different resident estimate and separately included substantial numbers entering Brooklyn from elsewhere.
What the same resident arithmetic looks like today
The latest Census Bureau estimate available for Brooklyn is 2,653,963 residents on July 1, 2025. Applying Rav Moshe's rough illustration mechanically gives two different results:
- one-fourth of 2,653,963 is about 663,491;
- one-fifth is about 530,793.
The six hundred thousand line falls between them. That is exactly why the one-in-four or one-in-five language cannot honestly be turned into a fixed formula that settles the matter from the resident count alone. Rav Moshe called it an estimate, said cities may differ, and separately required consideration of entrants from elsewhere.
It is also why a simple statement that “Brooklyn has more than 600,000 residents” does not reproduce Rav Moshe's street-presence calculation. It answers a different numerical question. On an interpretation that treats 600,000 city residents as the relevant threshold, Brooklyn plainly exceeds the number. On Rav Moshe's more specific city-street analysis, the inquiry is how the resident population, density, street presence and entrants combine within the relevant area.
Commuters measure something different from residents
Modern statistics make it possible to distinguish resident population from working-day population, but they still do not directly measure the halachic question.
The Census Bureau defines a “commuter-adjusted population” as resident population, plus workers who work in the area, minus workers who live in the area. It is intended to estimate how many people are assumed to be present during normal business hours. This is much closer to a daytime-presence question than a resident census is, but it is still not a count of people in the streets.
The Census Bureau's published comparison of 2019 and 2021 found that Kings County had the largest absolute increase in commuter-adjusted population in the New York metropolitan area during that period. Brooklyn's resident population increased by roughly 81,000, while its commuter-adjusted population increased by about 300,000. The Bureau attributed much of the change to the dramatic rise in working from home: about 325,000 Kings County residents worked from home in 2021, compared with about 59,000 in 2019.
That example also shows why “commuters” cannot be treated as a timeless fixed addition to Brooklyn's population. Working patterns change. The Census Bureau expressly warns that commuter-adjusted population does not include students, customers, tourists and other transient visitors, and does not capture day-to-day differences in work schedules. Its 2019-to-2021 comparison also covers an exceptional period in working patterns, not a permanent daily headcount for Brooklyn.
Rav Moshe's own 1979 category was broader than commuters alone. His sentence included people arriving for commerce, visiting relatives and regular employment. A modern attempt to reconstruct that category would therefore require more than a single commuting table.
Annual visitor totals are not daily street counts
New York City Tourism + Conventions reported 65.0 million visitors to New York City in 2025. The figure covers the five boroughs over the entire year. It includes domestic and international visitors, overnight travel and other visits.
That is useful evidence of the enormous flow of people into New York City, but it does not establish how many visitors are in Brooklyn on a particular day, how many are simultaneously in public streets, or how many pass one particular road. It cannot simply be divided by 365 and treated as a daily shishim ribo figure. An annual visitation total and a daily street-presence count measure different things.
The same caution applies in the opposite direction. A commuter statistic should not be described as a visitor statistic, and the five-borough visitor total should not be attributed to Brooklyn. Each number must retain its date, geography and definition.
The numbers each approach actually needs
| Halachic calculation | Factual question | What the New York data can establish |
|---|---|---|
| 600,000 residents of the city | How many people reside in the relevant city? | Brooklyn had an estimated 2,653,963 residents on July 1, 2025, so the numerical threshold is exceeded on a resident-population reading. |
| Rav Moshe's city-street estimate | How many people are ordinarily found in the streets across the relevant city area, including relevant entrants? | Resident population is a starting point, not the whole calculation. Rav Moshe used a rough one-in-four or one-in-five estimate and separately counted entrants from elsewhere. |
| Residents plus daily entrants | Do residents together with people entering the city reach the relevant number? | Commuting data can measure one portion of daily movement, but students, customers, tourists, family visitors and other transients require other data. |
| 600,000 passing a particular road each day | How many people actually pass through that road? | Borough population, five-borough population and annual visitor totals do not answer this. The particular road requires a particular traffic or passage count. |
Rav Moshe himself applied that last distinction to Manhattan's bridges in Orach Chaim I:139. He reasoned that when the traffic was divided among the thirteen bridges and the tunnels then serving Manhattan, no individual bridge carried six hundred thousand people each day. Whatever the modern traffic numbers may be, the structure of the calculation is clear: a road-specific test requires road-specific evidence.
What the New York figures establish, and what they do not
Several conclusions can therefore be stated without mixing incompatible calculations.
Brooklyn is far above 600,000 permanent residents. New York City as a whole is larger still, but a five-borough total is not automatically a Brooklyn total. Rav Moshe's own Brooklyn analysis treated the borough as a separate geographic unit and counted both a large resident population and entrants from outside it.
His February 1979 factual premise should be quoted as his premise. The later Census intercensal series gives a substantially lower resident population for the same period, while Rav Moshe also relied on a separate estimate of close to a million entrants. Modern Brooklyn has about 2.65 million residents, and applying his rough one-in-four or one-in-five illustration to residents alone produces answers on opposite sides of 600,000. A serious application of his approach therefore cannot stop with the resident count.
At the same time, a literal daily-passage approach cannot be answered by citing the population of Brooklyn, the population of all New York City, or 65 million annual visitors. It requires evidence for the actual roadway or passage being classified.
These are different factual questions because they rest on different understandings of shishim ribo. The broader Brooklyn and reshus harabim discussion addresses how these numerical issues fit with the other halachos Rav Moshe applied to Brooklyn. Here, the essential point is simpler: before a New York number can be used in the halachic calculation, one must first know exactly what is being counted, over what geographic area, and over what period of time.