Experimental review of the Cambridge Travel to Work Area as a tool for informing housing policy

A Travel-to-work Area (TTWA) theoretically represents a self-contained labour market area in which all commuting occurs within the boundary of that area. It has been re-defined once a decade when analyses on commuting patterns drawn from the UK Censuses were completed. In December 2015, the Office of National Statistics (ONS) published TTWAs based on the 2011 Census results. TTWAs are used primarily to aid understanding of labour markets across the UK. However, residential location and commuting patterns can also contribute to understanding local housing markets. The conventional assumption is that local labour markets are spatial proxies for housing markets. Indeed, housing professionals have been employing TTWAs in this way in their strategic plans. One of the issues in using existing TTWA s in this way is that they do not allow for overlap. Consider a household with two earners, one of whom is commuting within the TTWA while the other is commuting to a business hub outside their TTWA. For example, Cambridge TTWA has now expanded as far south as Hertford and Harlow – settlements containing many London commuters. Taking Cambridge as our example we attempt in this paper to experimentally identify commuting areas for Cambridge that lie within the boundaries of other employment hubs, such as Ely. In this way we can start to address the reality that TTWAs, certainly in terms of local housing markets, are not discrete – they overlap. The remainder of this brief report is structured as follows: Section 2 considers various alternative local housing market definitions and compares them to the 2011 Cambridge TTWA. Section 3 selects several employment hubs closest to Cambridge City, and uses Lower Super Output Areas as the basis for identifying the relevant local housing market area for the city and surrounding areas. In Section 4 we consider the housing needs (availability and affordability) of households of two earners, one of whom is commuting to work in the Ely employment hub while the other is commuting to Cambridge employment hub – producing a more complex but more accurate picture of local housing needs. Section 5 discusses the findings and suggests further research in respect of local housing markets in and around the Cambridge TTWA and beyond.