- Principal, Hertford College, Oxford (from 2005 to 2011)
 
	- Quondam Fellow, All Souls College (from 2005)
 
	- Lecturer in Historical Demography and Fellow, All Souls College (from 1991 to 2005)
 
	- Lecturer in Biological Anthropology, University College London (from 1980 to 1990)
 
	- Oil Demand Analyst, Shell UK Ltd (from 1979 to 1980)
 
	- Postgraduate, Churchill College, Cambridge (from 1975 to 1979)
 
	- Undergraduate, Hertford College, Oxford (from 1972 to 1975)
 
 
           
       
       
          
          
            
          
          
              
	- The Field and the Forge: Population, Production, and Power in the pre-Industrial West (New York: OUP, 2003)
 
	- Death and the Metropolis: Studies in the Historical Demography of London, 1670–1830 (New York: CUP, 1993)
 
 
           
       
       
          
            
          
          
              
	- Chairman, Animals in Science Committee (from 2011)
 
	- Member of the International Union for the Scientific Study of Population