There is already a large and growing literature on the effects of month of birth and school starting age on later academic and labour market outcomes. Given the importance of educational attainment in determining a range of later life outcomes - from the probability of being in work and the wage you receive, to health issues and criminal activity - these differences (which arise simply because of the month in which you were born) have the potential to affect individuals throughout their lives. But it is not only educational attainment that has long-lasting effects: there is a body of literature which emphasises the significant effects that a whole range of skills and behaviours developed and exhibited during childhood - including cognitive, non-cognitive, behavioural, social and emotional skills, and anti-social and other risky behaviours (e.g. smoking, drinking and drug use) - may have on later outcomes.

There are a number of reasons why we might expect month of birth (and the age at which you start school and sit academic tests) to affect the development of these skills. For example, whether you enjoy school has been found to be correlated not only with later academic performance, but also with engagement in a range of risky behaviours (including smoking, drinking and cannabis use), all of which may create health costs later in life. Similarly, motivation and perseverance on particular tasks have been found to be significantly positively associated with adult wages, even after taking differences in educational attainment into account. If consistently being amongst the youngest (and perhaps also the smallest) in your class affects your enjoyment of school and/or your motivation and determination to do well (amongst other things), then the month in which you were born - and the age at which you start school and sit academic tests - may have long-term consequences far beyond those captured by educational attainment alone.

Despite these (and other) potentially important repercussions, however, there is currently little evidence available regarding the extent to which month of birth is associated with the development of these types of skills and behaviours. Nor has there been any attempt to investigate whether particular school admissions policies either mitigate or propagate these relationships. The main aims of the proposed programme of research are thus:

1) To identify the impact of month of birth on the development of a range of key skills - including cognitive, non-cognitive, behavioural, social and emotional skills - and engagement in a range of risky behaviours - including smoking, drinking and anti-social behaviour - amongst today's children, from birth through to early adulthood. This work will extend far beyond the scope of previous research in this area - both in terms of the range of skills and behaviours considered, and the ability to consider recent cohorts of children - enabling us to build up a more complete picture of the impact that month of birth has on children's lives within the current policy environment.

2) To identify the best school admissions policy - in terms of all-round skill development and overall behaviour, as well as educational attainment - for a child born towards the end of the academic year, with a view to making clear and practical policy recommendations.

We intend to address our stated research aims using data on three separate contemporary cohorts of children which, together, will enable us to investigate how month of birth and school admissions policies combine to affect skill development and engagement in risky behaviours from birth through to early adulthood. These datasets are the MCS, ALSPAC, and the LSYPE. All three datasets contain excellent information on a range of cognitive and non-cognitive (including behavioural, social and emotional) skills, as well as details of engagement in a variety of risky behaviours. Furthermore, they have also been linked to administrative data on educational attainment.

In addition to data on the range of skills and behaviours that we are interested in, we also need information about the admissions policies that were in place when our cohorts of children started school. This broadly corresponds to 2005-06 or 2006-07 for the MCS, to 1995-96, 1996-97 or 1997-98 for ALSPAC, and to 1994-95 for the LSYPE. In 2004-05, members of the proposed research team started collecting annual admissions policy information from every LEA in England. We also collected retrospective information going back to 1989-90 for the majority of areas. This is a unique data resource, which will enable us to determine the admissions policy regime under which each child started school, and hence to assess which is the "best" admissions policy for children born towards the end of the academic year.

To estimate the impact of month of birth on a wide range of skills and behaviours, we intend to adopt a similar methodology to that used by Crawford, Dearden & Meghir (2007). We describe this methodology here by referring to a comparison of outcomes between August- and September-born children (i.e. those born at the very start and end of the academic year), but it is straightforward to extend this analysis to compare children born in all months at once (which is the approach we would adopt in our research).

In seeking to identify the impact of month of birth on any outcome, one needs to compare individuals who differ only to the extent that they were born in different months. If we are able to assume that date of birth is random, then we may simply compare the outcomes of children born in August with those of children born in September (for example). For date of birth to be random, we need two conditions to hold:

a) Parents with different characteristics - both observed and unobserved (to the researcher) - do not choose to have children in different months.

b) Parents with children born in different months do not differentially respond to survey questionnaires. (This is specific to our reliance on survey data for this project.)

If we are not convinced that these two conditions hold, then it will be necessary to control for all other outcome-relevant characteristics (aside from month of birth) in order to recover the true causal impact of month of birth on particular skills and behaviours. Given the extremely rich nature of the survey data we intend to use for this project (described above), it should be sufficient to do this using a simple linear regression framework.

To go further and identify which admissions policy is "best" for children born at the end of the academic year, we need to make an additional assumption:

c) The admissions policy adopted by the Local Education Authority does not reflect outcome-relevant unobserved differences between areas (or individuals living in areas).

Again, the very wide range of characteristics that we are able to observe in our survey datasets (described above) means that we should be able to simply repeat this analysis for children who start school under different admissions policy regimes, in order to test whether the impact of month of birth differs by admissions policy