Prevalencia de adherencia al uso de audífonos

A second alternative is to continue using the quantile approach that has been useful for the EJM previously but to reduce it to the simplest possible pattern that captures the concepts of job polarisation and upgrading. The simplest possible expression of the quantile approach for our purposes is terciles. Classifying jobs (occupation by sector combinations) into three groups of approximately equal size, ranked from low to high wages, can provide a sufficiently synthetic way to analyse structural employment change by region. Terciles can capture both polarisation (growth of the top and bottom terciles relative to middle) and upgrading (growth in the upper terciles relative to lower), as well as their mirror concepts of middle-biased growth (relative expansion of the middle tercile compared to the other two) and downgrading (relative expansion in lower terciles). When analysing changes in the relative composition of employment, terciles also have the advantage of requiring only two parameters to represent any pattern: if the three terciles must add up to 100%, then a structure of employment can be perfectly described just by representing two of the terciles, such as the bottom and top ones. For instance, if the terciles are initially equal in share (33.3%, 33.3%, 33.3%), and after some years the top and bottom terciles expand by 2 percentage points (35.3%, 29.3%, 35.3%), just by showing the change in the top and bottom terciles (+2 percentage points, +2 percentage points), the change in the middle (-4 percentage points) can be inferred because the three values must add up to 0. In other words, when analysing compositional change, terciles make it possible to characterise any pattern of job polarisation and upgrading with only two parameters.

The main disadvantage of terciles is that they are less precise than quintiles or deciles and therefore can miss some developments at a finer level of granularity. However, since the large number of observations (regions) requires more parsimony, this can be understood as an advantage too: only very clear cases of job polarisation and upgrading are observed, while developments at a more detailed level are abstracted away.

Grouping the jobs into terciles provides the necessary simplification of the analysis. However, how can comparability be ensured, given the large initial structural differences across European regions, as previously discussed? Our solution to this problem is to change the reference structure for analysing change over time: instead of using the initial structure of each region as the yardstick to analyse its change, the overall EU structure of employment – as approximated by the employment data from nine Member States accounting for over three-quarters of EU workers – in each year is used as a consistent point of reference for all European regions. Change is then analysed in terms of

convergence towards or divergence from that structure.

This is a subtle but significant departure from the way structural change is normally analysed in the EJM. The regional analysis is constructed as follows. First, an average normalised ranking is calculated for each job in the nine EU countries covered in this study in the first year of analysis. For instance, the job of secretary in the construction industry occupies a slightly different percentile position in each country (it may have a percentile position of 37.3 in Spain, 40.7 in France, and so on). The weighted average of the nine percentile positions for the same job across all countries could, for instance, be 39.5. This average percentile position is then renormalised according to overall EU employment, to allocate all jobs in three equal-sized groups (terciles), ranked from lowest to highest average wage. In the example, the job of secretary in the construction industry would be defined as a mid-paid job, because it would fall in the middle tercile of the EU as a whole. Then, a simple calculation for each region establishes what is the actual share of employment for each of those terciles: the distance from the share of the nine Member States (which is 33.3% by construction) indicates how a given region differs from the average employment structure for the nine. For instance, if a region’s employment comprises 25% low-paid jobs, 30% mid-paid jobs and 45% high-paid jobs, its employment structure is clearly more upgraded than that of the EU (since the same three categories of jobs account for an equal share of 33% in the nine Member States as a whole). If the exact same exercise is carried out at the end of the period of analysis, and the same region’s employment turns out to be made up of 35% low-paid jobs, 30% mid-paid jobs and 35% high-paid jobs, it can be concluded that the region is now closer to the average employment structure of the nine Member States. In addition, in relative terms, its structure has downgraded, because over the period, its share of low-paid jobs has expanded by 10% and its share of high-paid jobs has decreased by the same amount, while the share of mid-paid jobs has remained stable. This approach achieves several things simultaneously. Firstly, it ensures a high degree of comparability: the jobs classified as high-paid, mid-paid or low-paid are exactly the same across all regions, according to their average wage in all nine countries, facilitating comparison of the regions’ different employment structures. Secondly, it takes into account the initial (and final) large structural differences across European regions, because the initial (and final) shares of high-paid, mid-paid and low-paid jobs reflect how different each region is from the average EU employment structure. Thirdly, it allows the identification of patterns of job polarisation and upgrading over time, since the difference between the initial and the final structure reflects structural change in a similar way to the standard EJM approach (although as previously mentioned, not entirely

identical). An additional benefit of this approach is that it addresses the issue of convergence and divergence in the employment structures of regions towards the EU average, a subject of great interest on its own. To sum up, in this section the concepts of job polarisation and upgrading are explored from both a static and a dynamic perspective.

1. From a static perspective, it analyses whether each region is polarised or upgraded in its