Initial result analysis by demographic process

Spatial variances in small areas are also found in the different demographic processes. Two wards, Headingley and Cookridge, have been selected to demonstrate such variances in the small areas in Leeds. Headingley is a ward in the city centre that is popular for the university student accommodation, while Cookridge is a more established suburban area. So the two local populations differ considerably. The two wards will be used as examples throughout the demographic process analyses.

4.8.3.1 Initial Mortality result analysis

The simulation results from the Mortality module have been illustrated in Figure 4.18. The current model uses one set of survival probabilities by age, sex and location, therefore the mortality rates do not change over time. This limitation is addressed in further developments of the model, which are described in chapter 5.

The initial results for year 2030 suggest that mortality changes systematically with the age. Both small area populations demonstrate a smaller number of deaths in younger ages. In fact, there is no mortality for ages under 20 in Cookridge and there are only a small number of deaths in Headingley. Mortality starts to increase gradually with age from age 40 onwards and reached the peak around the ages 70-79 and then gradually reduces. However, we have to take into consideration that there are very small numbers of population in the very old ages such as ages 90+. Females in most ages experience fewer deaths than males, except those in ages 70-79 and 90+ in Cookridge and those in ages 40-49 and 80-89 in Headingley.

Cookridge

Headingley

Figure 4.18 Ward level projections of mortality in 2030

Overall, Headingley has a larger number of deaths in almost all age bands than Cookridge. This is not surprising, as Headingley also has a bigger base population than Cookridge, as analysed in previous sections. The number of deaths for ages 50 and over in Headingley is substantially higher than that in Cookridge (Figure 4.18).

4.8.3.2 Initial Household Formation result analysis

In the Household Formation module, the household formation probabilities are assumed to be constant again from year 2001. Figure 4.19 shows the household formation projections for Headingley and Cookridge.

Cookridge

Headingley

Figure 4.19 Ward level projections of household formation in 2030

The simulation results in year 2030 show that there are more household formations in Headingley than in Cookridge, due to the larger population in Headingley. However, the initial result analysis indicates that people in both 152

Headingley and Cookridge are most likely to form a household between the ages of 20 to 30. From the age of 16, a small number of people start to form their households. Such numbers reached a peak at ages 20-29. Then the numbers gradually decrease in both areas and there are very few people that form their households beyond the age 60.

From the ages over 60, the numbers of household formations in both wards are smaller. Compared to Headingley, there are fewer males than females in ages 16-39 that form households in Cookridge; while the contrary relationship holds in Headingley. From ages 40 onwards, there are more males forming households than females in both wards. Although there is a substantial drop in the household formation from the ages 40-49 for both sexes, the reduction in the number of females forming households over ages 40 are significantly smaller than males. In Cookridge, there are hardly any females forming households from the ages 50 onwards.

4.8.3.3 Initial Fertility result analysis

In the Fertility module, the fertility probabilities generated on the basis of information from year 2001 are applied over time to the women at risk. The simulated fertility results of year 2030 in small areas have been analysed. The analysis of results from Cookridge and Headingley in Figure 4.20 indicates differences in births in the two small areas.

In Figure 4.20, fertility projections in year 2030 show that few females in Headingley give birth to babies at ages under 16 (ages 12-15 in this model); while there are no births in Cookridge until the age 16. Then the fertility increases with age and the numbers of births in both Cookridge and Headingley are found in the age groups of mothers from 20 to 39. Then the fertility drops substantially for females in both areas from the age 40 onwards. There are no births for females aged over 45 in both areas. Such patterns are consistent with the national projection. Overall, Headingley has more births than Cookridge, especially to women aged 20 to 39. This is partly caused by the large projected population in Headingley, as there are many young women ages 16-29 in this area. However, most university

students are unlikely to give birth to babies in reality. This indicates the limitation in the initial model results and this will be addressed in model refinement, which will be discussed in Chapters 5 and 6.

Figure 4.20 Ward level projections of fertility in 2030

4.8.3.4 Initial Health Change result analysis

In the Health Change module, the changes in general health for population aged 65 or over in small areas are modelled to facilitate the public health planning within an ageing population. The health changes are simulated on the basis of changes in general health status of the population aged 65 onwards, from “Good” to “Fairly Good”, “Fairly Good” to “Not Good” and “Not Good” to “Formal Care”, indicating an individual’s general health has deteriorated to a status where informal care at home is no longer suitable and the person must be transferred into a formal care facility. Projected results in Cookridge and Headingley in year 2030 have been analysed by sex and age groups, as presented in Figure 4.21.

Overall, there are more counts of health changes in Headingley than in Cookridge, due to the larger population in Headingley. Most health changes occur at ages 65-69.Then the number of changes gradually reduces with age. There are very few health changes from age 80 onwards. In both wards, more females experience general health status change from “Fairly Good” health to “Not Good” than males at ages 65-69. On the other hand, this has changed at ages 70-74, where more males experience general health status 154

changing from “Fairly Good” health to “Not Good” than females and this pattern continues into the age groups 75-79.

Cookridge

Headingley

Figure 4.21 Ward level projections of health changes in 2030 by sex and age

In terms of the “Formal Care” demand, there is a consistently higher demand from the females than males in most of the older age groups (ages 65 and over). This may indicate a faster deterioration in females’ general health from “Not Good” to “Formal Care” than in male’s for those aged 65 or over. This may indicate that more females require formal care in part because male partner dies first, leaving them living alone without available in-house support. Such patterns are also consistent with the recent

population trends reported by ONS that women live longer in poorer health than men do in UK (ONS, 2008c). Men have shorter lives.

4.8.3.5 Initial Migration result analysis

The migration simulation results of Cookridge and Headingley in 2030 are analysed and the analysis indicates that there are significant variances in the migration patterns in small areas. Overall, there is a much higher degree of migration in Headingley than in Cookridge. However, there is very little difference between the in-migration and the out-migration movements in both wards, as indicated by Figures 4.23 and 4.24. Such patterns are consistent in both household and individual migrations.

Figure 4.22 Ward level projections of in-migration in 2030

Figure 4.23 Ward level projections of out-migration in 2030

The net-migration analysis is illustrated in Figure 4.24. Projections in Cookridge indicate that there are more household migrations than individual migrations in 2030, but the difference between two types of migration is not big. Net-migration projection results in Headingley, however, indicate that there are substantially more individual migrations than the household migrations in the area. In contrast to net-migration in Cookridge, net- migration of individual migration is about four times of that of household migration in Headingley. This may reflect the local contexts of the two wards. Cookridge is a more established suburban area, while Headingley is an area popular with student accommodations in the city centre. Such small area characteristics also help explain the difference between the household and individual migrations in the two areas. The much higher individual migration level may be due to the impact of university student migration in this area, while most residents in Cookridge are families so they are more likely to move as a whole household. As most students are full-time student in ages 16-29, who leave their homes and come to Leeds to complete their higher education. Although they are highly mobile during their study duration, they are unlikely to move with households.

Figure 4.24 Ward level projections of net-migration in 2030