1. 四口之家的收入总和普遍最高，举4个州为例，好像我一眼扫过，全美国只有麻州6，7口之家比4口之家总收入（不是人均啊！）高，也就是说，绝大部分地区，不但是越生越穷，而且越穷越生：
California
Total: 70,029
2-person families 64,878
3-person families 70,890
4-person families 79,477
5-person families 68,073
6-person families 67,499
7-or-more-person families 74,290

Massachusetts
Total: 81,569
2-person families 69,451
3-person families 82,591
4-person families 99,648
5-person families 96,141
6-person families 104,012
7-or-more-person families 106,985

New York
Total: 67,877
2-person families 58,109
3-person families 69,421
4-person families 82,457
5-person families 80,515
6-person families 77,393
7-or-more-person families 78,728

South Carolina
Total: 55,664
2-person families 51,374
3-person families 55,296
4-person families 65,655
5-person families 64,046
6-person families 60,504
7-or-more-person families 54,201


2. 不工作比一家只有一个人工作，收入没差多少阿，也举这4个州的例子：
California
Total: 70,029
No earners (dollars) 31,178
1 earner (dollars) 48,140
2 earners (dollars) 89,164
3 or more earners (dollars) 101,837

Massachusetts
Total: 81,569
No earners (dollars) 29,827
1 earner (dollars) 53,505
2 earners (dollars) 98,887
3 or more earners (dollars) 115,622

New York
Total: 67,877
No earners (dollars) 27,891
1 earner (dollars) 46,485
2 earners (dollars) 87,498
3 or more earners (dollars) 107,946

South Carolina
Total: 55,664
No earners (dollars) 28,157
1 earner (dollars) 39,191
2 earners (dollars) 73,065
3 or more earners (dollars) 89,087