My 'knowledge' on goats is indeed received wisdom, but it has been received from people I respect with enormous and varied field experience. They too have noted the lack of an empirical basis and this debate has encouraged me to encourage someone I know who is writing a literature review on this subject to finish, and I am forwarding this blog and comments to others whom I know are intersted in the hope they will also contribute. I would draw your attention to work done on the impacts of goats and other livestock in arid northern Kenya by Oba et al. in Land Degradation 14: 83-94, 2002 (http://www3.interscience.wiley.com/journal/98515505/abstract?CRETRY=1&SRETRY=0) which concludes as follows: ... understanding plant species responses to grazing pressure and seasonality needs to consider multiple scale effects and the dogmatic notions about degradation of the arid zone rangelands at the coarse scales should be reconsidered. Land degradation assessments in the arid zones should focus at the fine scale. The importance of the fine scale is echoed by the fascinating paper by Andre Marin (above) on nomadic herders’ observations of climate change in Global Environmental Change 20: 162-176, 2010 (http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VFV-4XRJGP2-1&_user=1916569&_coverDate=02%2F28%2F2010&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1203254887&_rerunOrigin=google&_acct=C000055300&_version=1&_urlVersion=0&_userid=1916569&md5=56b429781a3f96a60eeed909d1a2e0ab). This describes the increasingly fine-grained 'patchiness' of precipitation. This is important because Mongolia's grasslands are mostly a non-equilibrium system, that is, they can change year by year depending on a host of factors and trying to attribute a single cause to a particular change is risky. That said, politicians need general guidance and principles and the fine scale is anathema to policy. I will take this debate as a challenge to further our understanding so that we can provide well-supported advice to government. Relevant to all this, later this year our NEMO2 project will include an analysis of data on pasture quality changes collected by MercyCorps under our Sustainable Livelihoods Project's livestock early warning system, and also determine a robust methodology that will allow the attribution of changes in pasture use to project-level interventions that seek to improve pasture management.