The United Nations has undertaken an important Bayesian sensitivity analysis of global population burden based on life expectancy projection at birth in future decades. The 2017 95% prediction interval of 2090 average life expectancy rises as high as +6 (106, in Century Representation Form) by 2090, with dramatic, ongoing, layered consequences on world population and demography should that happen. The prediction interval is extremely wide, and the United Nations can not be certain. Organizations like the Methuselah Foundation are working toward an end to senescence and practically unlimited human lifespan. If successful, the demographic implications for human population will be greater in effective multiplier terms than any experienced in the last five centuries if maximum lifespan or the birthrate remain unlimited by law. Modern Malthusian predictions of overpopulation based on increased longevity have been criticized on the same basis as general population alarmism (see Malthusianism).