(PSICK) - significantly lower the number of years that they expected to live. While not statistically significant for the male sample, women who are concerned with becoming disabled (DISAB) also expected to live a shorter life. Both men and women took strong signals about how long they should expect to live from their parents' experience. Whether a parent (of the same sex) is alive - or if deceased, the age at which that parent died - has a strong, positive effect on the subjective life expectancy of both sexes. The regressions explain 59% and 62% of the variation among responses from men and women, respectively, suggesting that respondents' expectations contain a substantial rational component. These results are similar to those reported in the studies using data from the United States, cited above.

# VI. **Results**

I have separated the empirical analysis of individual preferences to mitigate poverty in old age into two parts. In the first, tobit regressions are performed to show the determinants of reported _density of contributions_ (CONDEN): the total number of months respondents have contributed to the social security/pension system, divided by their total number of economically active months.<sup>4</sup> ' Since the dependent variable in the tobit regressions is constructed from respondents' recollections extending back to when they first contributed to social security, there are few remaining pre-determined variables (other than age, education and for younger respondents assets held ten years prior to the survey) to act as exogenous regressors. Thus the results of the tobits should be interpreted with caution. For this reason probit regressions - similar to those used in Barrientos (1998), Holzmann, Packard and Cuesta (2000), and Packard, et al (2001) to measure the probability that a respondent is contributing at the time of the PRIESO, are used in the second part of the analysis. Conceptually, _"contribution density"_ in the tobit regressions is the integral over the individual's working life of the binary _"contributes/does not contribute "_ in the probits that follow.

Additionally, motivated by the results of the economic experiments discussed in Barr and Packard (2002), the same tobit and probit regressions are estimated on a sample of self employed men, first without and then with the measures of time preference and risk tolerance constructed for the sub sample of PRIESO respondents who participated in the experiment.

# _(vi.a) Tobit Regressions on Contribution Density_

The results of the tobit regressions on contribution density for men and women are presented in Table 8. It bears repeating that there are a limited number of truly predetermined variables in the PRIESO data that can act as regressors in this model. Since I have chosen to include potentially endogenous right-hand-side variables in the

> 41 Since only those respondents who are affiliated to the pension system can report contributions, and to allow for the possibility that affiliated workers, particularly affiliated women are a self-selected group, I first experimented with a Heckman (1979) two-step procedure. The dependent variable in the first step was a binary equal to I if the respondent was affiliated to the pension system, and in the second step the dependent variable was contribution density. However, tests for significant correlation of the error terns in the two regressions rejected the Heckman procedure.

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