Estimating missing GDP

The plot on the right shows your original GDP data (on top), followed by each of the three xts objects you generated using different techniques for handling missingness: locf, nocb, and approx. Your decision about which technique to use must be informed by the circumstances, including what the data represents and what relationships you can identify from the non-missing data.

Based on your understanding of the data, which method makes the most sense in this context?