# Understanding the Stock and Wise option value model

Is there any Python or Julia script computationally explaining the Stock and Wise (1990) option value retirement model?

Individuals have a probability of surviving from period t to period s (π_{s,t}), but die with certainty by age T. Discounted lifetime utility is:

V_{t}(r)=\sum_{s=t}^{r-1} \beta^{s-t} \pi_{s, t} U_{w}\left(Y_{s}^{w}\right)+\sum_{s=r}^{T} \beta^{s-t} \pi_{s, t} U_{r}\left(Y_{s}^{R}\right)

(extracted from Blundell, R., French, E., & Tetlow, G. (2016). Retirement Incentives and Labor Supply. In J. (John R. ) Piggott & A. D. Woodland (Eds.), Handbook of the economics of population aging (pp. 458–566). Elsevier)

Hi @sbac ,

Not that I know about. It’s a nice suggestion though. I’m pretty flat out with teaching right now but if I can find time I might try coding it up.

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