>What is your source for 1968 as the year of
>greatest income equality in the US?
The Census Bureau's annual gini indexes. Quintile ratios tell a slightly different story; the ratio of the richest quintile to the poorest bottomed out in 1974, though the top/middle ratio also bottomed out in 1968.
I know the Gini index isn't a perfect single measure - that Ginis, Atkinsons and Theils are all sensitive to different points of the distribution. I suppose the cautious thing to do is to say that U.S. income inequality bottomed out in the late 60s/early 70s and has risen pretty steadily ever since.
Here's the gini history for families and households since 1947. I've got a (somewhat dated) explanation of ginis at <http://www.panix.com/~dhenwood/Gini_supplement.html>.
Doug
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GINI INDEX - US FAMILIES AND HOUSEHOLDS
family h'hold
1947 0.376
1948 0.371
1949 0.378
1950 0.379
1951 0.363
1952 0.368
1953 0.359
1954 0.371
1955 0.363
1956 0.358
1957 0.351
1958 0.354
1959 0.361
1960 0.364
1961 0.374
1962 0.362
1963 0.362
1964 0.361
1965 0.356
1966 0.349
1967 0.358 0.399
1968 0.348 0.388
1969 0.349 0.391
1970 0.353 0.394
1971 0.355 0.396
1972 0.359 0.401
1973 0.356 0.397
1974 0.355 0.395
1975 0.357 0.397
1976 0.358 0.398
1977 0.363 0.402
1978 0.363 0.402
1979 0.365 0.404
1980 0.365 0.403
1981 0.369 0.406
1982 0.380 0.412
1983 0.382 0.414
1984 0.383 0.415
1985 0.389 0.419
1986 0.392 0.425
1987 0.393 0.426
1988 0.395 0.427
1989 0.401 0.431
1990 0.396 0.428
1991 0.397 0.428
1992 0.404 0.434
1993 0.429 0.454
1994 0.426 0.456
1995 0.421 0.450
1996 0.425 0.455
1997 0.429 0.459