In this episode Miles is joined by Dr James Tucker and Sarah Caul MBE to talk about how and why the Office for National Statistics count births and deaths, and what current fertility trends might mean for the future population. They look at the impact of popular culture on the most common baby names in England and Wales, and discuss the new significance of a dataset that was itself buried for 50 years.   Transcript:   MILES FLETCHER   I’m Miles Fletcher and this episode of ‘Statistically Speaking’, the official ONS podcast, is literally a matter of life and death. Specifically how and why we count births and deaths and what those numbers are telling us. We'll talk about the possible impacts of declining fertility rates in the UK and of children being born to older parents. And at the other end of life we'll look at the new significance of a dataset that was itself almost buried for 50 years I'm joined here at ONS by two people who lead on all our data around births and deaths - Head of Analysis in our health and life events teams, James Tucker, and our very own Head of Mortality, Sarah Caul MBE, honoured for her work during the pandemic about which we will talk later.   Starting with you then James, at the beginning as it were, with births - how does the ONS gather information about the number of children being born in England and Wales week in, week out?    JAMES TUCKER  So the registration of births is a service that's carried out by local registration services in partnership with the general register office in England and Wales and the good thing about this, from the perspective of having a really nice complete dataset, is that birth registrations are actually a legal requirement, giving us a really comprehensive picture of births in the countries.    MF  So we gather the numbers, we add them up, what do we do with the information then?    JT  So there's a couple of ways that we look at the data. One is to simply look at the number of births per year. So for example, we're looking at about 600,000 births per year at the moment. But an alternative approach is to use what we call the ‘total fertility’ rate, which is basically the average number of live children that women might expect to have during their childbearing lifespan. So it's a better measure than simply looking at the trends in the number of births because it accounts for changes in the size and age structure of the population.    MF  So it has a sort of multi-dimensional value then statistically that you can use to infer various things about the age at which people are likely to have children, and how many they're likely to have.    JT  That's exactly right. So we've seen some changes in the total fertility rate in recent years. So if you've heard the expression 2.4 children as describing the average number of children per family it's now considerably lower than that. In fact, it hit a record low in 2020 when the total fertility rate was 1.58.    MF  That's a sharp decline. In fact, though, you've got to go as far back as 1970, when the current series began, that's when it really was 2.4. What's really striking is if you look at that graph, the decline that happened between 1970 and about 1977 - very sharp decline there. Do we know what happened during that period? What were the factors driving that particularly?    JT  I think there can be all sorts of socio-economic factors affecting the fertility rate: improved access to contraception, reduction in mortality rates of children under five, which can result in women having fewer children. And also, more recently, as we've seen the average age of mothers going up, we might see some lower levels of fertility due to difficulties conceiving because of that postponement in childbearing.    MF  Sarah, I can see you want to come in on this.    SARAH CAUL  So my mother had three children by the time she was 30, and growing u