When Leaf returned three years later, that same man claimed to be 134 years old. Leaf then persuaded Dr. Richard Mazess of the University of Wisconsin Madison and Dr. Sylvia Forman of the University of California Berkeley to help determine the correct ages of Vilcabamba's elderly population. They reached the conclusion that there was not a single centenarian living in Vilcabamba. The oldest person in the village was found to be 96 years old. The average age of those claiming to be over 100 years was actually 86 years. The researchers presented these results on February 27, 1978, at a workshop at the National Institutes of Health in Bethesda, Md.  Far from being the 'Valley of Longevity,' the researchers concluded that "Individual longevity in Vilcabamba is little, if any, different from that found throughout the rest of the world." Further, they reported that "Life expectancy (corrected for exaggeration) at all ages in Vilcabamba (and Loja) is, in fact, less than in the U.S."  Mazess and Forman identified two sources of error. First, the villagers systematically exaggerated their ages and the older they grew, the greater their exaggerations became. Mazess and Forman provided the example of Miguel Carpio Mendieta (MCM):  Apparently MCM did not begin exaggerating his age until later in life. When he was 61 in 1944 he reported an age of "70". Five years later he was reputedly "80". In 1970, at age 87, he was reputedly "121", and in 1974, at 91, he was "127". The researchers speculated that the villagers had originally exaggerated their ages in order to gain prestige in the community. This practice appeared to have been occurring for generations, long before academic researchers had arrived in the village. Additionally Dr. Leaf speculated that the international publicity, and subsequent rise in tourism, may have encouraged the villagers' exaggerations to grow more prolific. The second source of error was the widespread use of identical names in the small community. This had initially confused researchers who had studied the baptismal and birth records. The birth-date of an identically named uncle or father would appear to confirm the extreme longevity of a resident. By asking the Vilcabambans for the names of their godparents, the researchers were able to identify the correct records for each resident. It turned out that Vilcabamba did actually have a higher-than-normal percentage of elderly people, but that this was caused by migration patterns: Young people tended to move out of the area, while the elderly moved in.