| | Valley Stream, NY | Emerson, NJ | United States |
| Population | 40,304 | 7,317 | 329,725,481 |
| Female Population | 53.2% | 52.4% | 50.5% |
| Male Population | 46.8% | 47.6% | 49.5% |
| Median Age | 42 | 47.5 | 38.4 |
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| Population - 2010 | 37,426 | 7,394 | 309,327,143 |
| Population - 2000 | 36,368 | 7,197 | 285,036,114 |
| Population - 1990 | 33,946 | 6,930 | 251,960,433 |
| Pop. 2000 to Now | 2.3% | 5.1% | 15.6% |
| Pop. 1990 to Now | 9.6% | 9.1% | 30.8% |
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| Population Density | 11,584.9 | 3,279.7 | 93.4 |
| Land Area | 3.5 | 2.2 | 3,531,905.4 |
| Water Area | 0.0 | 0.2 | 264,836.8 |
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| Est. Total Population By Age | | | |
| | Valley Stream, NY | Emerson, NJ | United States |
| Age 0 to 4 | 4.7% | 4.8% | 5.9% |
| Age 5 to 9 | 4.6% | 3.6% | 6.1% |
| Age 10 to 14 | 6.2% | 7.6% | 6.6% |
| Age 15 to 17 | 4.3% | 3.3% | 3.9% |
| Age 18 to 20 | 4.1% | 3.3% | 4.0% |
| Age 21 to 24 | 4.8% | 3.8% | 5.2% |
| Age 25 to 34 | 12.4% | 7.6% | 13.8% |
| Age 35 to 44 | 13.0% | 12.5% | 12.9% |
| Age 45 to 54 | 15.7% | 16.0% | 12.6% |
| Age 55 to 59 | 6.3% | 9.4% | 6.7% |
| Age 60 to 64 | 8.6% | 5.4% | 6.3% |
| Age 65 to 74 | 10.1% | 14.9% | 9.6% |
| Age 75 to 84 | 2.9% | 4.2% | 4.5% |
| Age 85 and over | 2.3% | 3.7% | 1.9% |
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| Race | | | |
| | Valley Stream, NY | Emerson, NJ | United States |
| White | 28.5% | 75.7% | 59.4% |
| Black | 26.5% | 0.8% | 12.2% |
| Asian | 14.7% | 13.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 3.0% | 0.0% | 0.4% |
| Two or More Races | 5.0% | 1.0% | 3.2% |
| Hispanic | 22.3% | 9.4% | 18.4% |
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| Marriage & Family | | | |
| | Valley Stream, NY | Emerson, NJ | United States |
| Married Population | 53.7% | 68.3% | 49.8% |
| Currently Married | 52.7% | 67.5% | 48.0% |
| Married but Separated | 1.0% | 0.8% | 1.8% |
| Single Population | 46.3% | 31.7% | 50.2% |
| Never Married | 33.1% | 20.6% | 33.8% |
| Divorced | 7.5% | 4.7% | 10.8% |
| Widowed | 5.7% | 6.5% | 5.6% |
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| Household Size | 3.21 | 2.79 | 2.60 |
| Households | 12,520 | 2,537 | 124,010,992 |
| Family Households | 10,137 | 2,110 | 80,755,759 |
| Married couple, w/children | 35.3% | 34.5% | 30.5% |
| Married couple, no children | 38.7% | 58.1% | 42.9% |
| Non Family Households | 2,383 | 427 | 43,255,233 |
| Single householder, w/children | 11.8% | 2.3% | 15.8% |
| Single householder, no children | 14.3% | 5.1% | 10.8% |