88 BUREAU OF AMERICAN ETHNOLOGY [Bull. 197 



the reported total population jumps from 26,624 in 1910 to 30,006 in 

 1911. This implausible increase was due largely to an unexplained 

 increase in the estimated population of the Northern Agency (from 

 5,500 in 1910 to 8,000 in 1911) together with a 10 percent increase in 

 the estimated population of the Leupp and Southern Agencies (from 

 10,000 in 1910 to 11,000 in 1911) . The latter increase can be attributed 

 to the fact that the two agencies were not separately reported in 1910, 

 while in 1911, the Southern Agency figure was again given as 10,000, 

 but the Leupp Agency was separately reported as 1,000. The crudity 

 of these estimates is further indicated by the fact that the figures of 

 10,000 for the Southern and 8,000 for the Northern Agencies are 

 repeated, without change, in the reports for each year from 1911 to 

 1915. 



From 1911 to 1918, the estimated total Navaho population as given 

 by the Navajo Agency increased, with minor changes, from 30,006 to 

 31,397, which would imply an average annual rate of increase of only 

 0.65 percent. However, it should be noted that the 1911 figure is about 

 one-third higher than the figure reported in the 1910 census, so that 

 the implicit rate of increase camiot be relied upon. 



The figures reported for 1918 and 1919 are particularly interesting 

 because of their apparent reflection of the impact of the influenza 

 pandemic. The total Navaho population in 1919 was estimated as 

 29,672, a decline of 5.5 percent from the figure of the previous year. 

 Examining the data for the separate agencies, it can be noted that 

 the Northern Agency reported a slight increase, the Leupp Agency 

 reported no change, and the remaining agencies reported declines of 

 varying severity. Although data on the causes of Navaho mortality 

 at this time are lacking, the indicated declines suggest that the esti- 

 mates given were not the mere repetitions or arbitrary upward revi- 

 sions that were so common in earlier years. 



In the early 1920's, the reported estimates of total Navaho popula- 

 tion continue to fluctuate between 30 and 32,000, with an unexplained 

 decline of 1.8 percent between 1922 and 1923, followed by an im- 

 plausible increase of 3.8 percent between 1925 and 1926. The aver- 

 age annual increase between 1919 and 1930, as implied in the figures 

 given by the Navajo Agency for those years, comes to 2.95 percent, 

 a rate which has only been exceeded m a few countries since World 

 War II. The fact that the implied rates of increase during the 1920's 

 are very high, while those of the 1910's are quite low, suggests that 

 the population estimates made around 1920 may have been seriously 

 deficient, despite the presumable impact of the uifluenza pandemic. 

 However, these rates lend greater support to the further hypothesis 

 that the 1910 figures submitted by the Navajo Agency were con- 

 siderably exaggerated. 



