12 (v) The degree of heterogeneity (or persistence) is measured as proposed by Mfincer (1982) by: I - X where X = (Pyr - **P.J/(Py,,u** - P,,). When X = 0, there is complete persistence in the unemployment experience which always affects the same individuals.

# Results.

Results are presented separately for men and women in Tables 15 and 16. For both, estimates are presented for different age and education groups. In the case of men, we use both the standard and alternative definitions of unemployment. Column (1) shows the unemplu,ment rate corresponding to a one-week observation period; column (2) indicates the proportion of the labor force unemployed at least once over the five successive quarterly surveys; column (3) corrects this estimate to indicate a range of likely estimates for the proportion of the labor force unemployed over one year period; column (4) indicates the upper limit of P in the case of perfect homogeneity of the labor force and perfect turnover week after week; column (5) presents the value of the persistence indicator; columns (6) and (7) indicate the sample size of each cell; N refers to the number of unemployed and LF to the labor for"e.

The distinction between a snapshot relative to a one-week period and an analysis covering one full year provides interesting insights. While only about 5 percent of all males are found unemployed over a given week (broader definition of unemployment) , between 18 and 20 percent will enter unemplovment over one year, ie. 4 times as many. As could be expected from previous analysis, rates differ between age and education groups. The most striking result refers to the 12-20 age group: over half of youth will experience at least one period of unemployment over a year. Beyond the age of 20, the proportion decreases sharply although it remains above average until the age of 30. The effect of age is also noticeable when one considers the persistence indicator: persistence increases with age. Unemployment is thus clearly more uniformly spread among youth, especially teenagers, than among adult workers. Experience acquired in the labor market protects workers frum the risk of unemployment. However, it induces greater heterogeneity.

Differences among education levels are less clear. Perisitence of unemployment appears to be higher at lower and higher levels of education, than at intermediate levels. However, the result may be biased as low educated groups are typically older. Small sample size unfortunately prevent us from measuring persistence by education levels for given age groups.

Results of the analysis of persistence of unemployment with data for women are consistent with those for men. Persistence is shown to increase with age and sharp differences exist between teenagers, young and adult women. Even using the most restrictive definition of unemployment, over one third of teenage women will experience unemployment over one year.

Finally, it is interesting to observe that, although unemployment rates are higher for women than for men, persistence is somewhat stronger among young men.

In sum, although unemployment rates in Mexico, as measured over one week period, are low compared to what is observed in other countries, in particular industrialized countries, unemployment is experienced by a significant fraction of the population: _15,c_ to 20% of men and women will experience at least one spell of unemployment over a one vear period. There are sharp differences between young and adult workers. About half of teenagers will experience unemployment over one