The last decade has seen widespread domestic financial deregulation in the industrial world, particularly in the United States, United Kingdom and the Nordic countries, resulting in an increase in competition both between banks and saving institutions (thrifts or building societies) as they moved into each others services, and within each-sector.' This opened up new financial options, particularly for households, the sector that was probably most affected by government regulation. For example, there was a significant increase in equity withdrawals from personal housing wealth in both the United Kingdom and United States over the ig8os.2 This period also saw a significant change in household consumption behaviour, the most dramatic illustration being the fall in the household saving ratio in those countries where the process of deregulation has gone furthest. This paper reports the results from estimating a model of household saving using regional data for the United Kingdom, with a particular emphasis on the interaction between household saving and financial deregulation. The estimates are used to calculate the relative importance of different factors in the fall in personal saving over the I98os. I conclude that deregulation lowered the equilibrium level of saving over the I98os, probably 2' percentage points per annum, as well as making saving significantly more dependent on changes in wealth, income and real interest rates. There have been a number of earlier empirical studies looking at the interaction between financial deregulation and household behaviour. Manchester and Poterba (i 989), Miles (I 992) and Koskela et al. (I 992) present empirical evidence on the interaction between deregulation, the housing market, and saving in the United States, United Kingdom and Finland, respectively. Others have estimated saving functions which include variables representing the effects of financial deregulation or have considered the impact of financial deregulation on liquidity constraints in consumption.3 The