As is well known, the conclusions of previous researches by Professors Cook and Borah in this series have been 1) that an unexpectedly large native population inhabited central Mexico at the time of the conquest; and 2) that this population declined by 90 percent or more in the century following 1519. Occasionally in previous studies the authors have touched on changes that took place after the early seventeenth century. But only with the present work do they survey systematically for any area all demographic data to the present. We have, then, for the first time a thorough analysis of population over the long term.

As is well known also, the previous studies have been challenged, the challenge consisting principally in the argument that the 1519 population figure was not so high, and the decline therefore not so drastic. Since the present work depends on the earlier ones for its sixteenth-century materials, it seems most unlikely that anything in this study will resolve the controversies. The authors’ position for the Mixteca Alta in the sixteenth century fits, matches, and re-expresses the position already taken for central Mexico as a whole. A short review is not the appropriate place to examine the evidence, but I should like to say here that in my opinion the Borah-Cook position is the right one.

A special interest attaches to the discussion of the period since 1600, where some new ground is broken. The change from a declining to an increasing population is put at about 1610. The ratio of total population to casados rose from 3.3 in the sixteenth century to 4.2 about 1660, rose further to 5.0 by the middle of the eighteenth century, and then became stable. The ratio of total population to tributaries in the same period shows a similar but slightly less pronounced curve. Data are relatively weak for the seventeenth century, and relatively abundant and reliable for the eighteenth, nineteenth, and twentieth centuries. The record of increase since 1610 shows two interruptions, one corresponding to the war for independence, the other to the Revolution of 1910. The population of the area approximately doubled from 1825 to 1880 and approximately doubled again from 1880 to 1960, but some districts (or ex-districts) changed much less than this and some much more.

The authors do not fully analyze the meaning of the recorded decrease between 1910 and 1921, and for this crucial period, as well as for the independence years, we are left uncertain as to whether or not recorded decline means real decline. It would be worth knowing if the events of 1810 had a greater effect on population than the events of 1910. Without actually making a promise the final sentence of this study allows for the possibility that a subsequent work will deal further with the evidence of the nineteenth and twentieth centuries.