Translations:Advanced Field Epi:Manual 1 - Disease Control and Eradication Programs/206/en

Often changes intended to control or eradicate livestock disease and benefit animal production measures may take years to fully implement. In addition costs may be higher in the beginning and then reduce over time and benefits may be lower in the beginning and slowly rise over time. It is very difficult to assess the impacts of these sorts of changes using partial budgets or gross margins analysis alone, mainly because of the time change in the value of money. One dollar earnt (or spent) now is not the same as one dollar earnt or spent in five years time, mainly because of the effects of things like inflation and discounting.