The amount (on a scale of 0-1) of the value of impact event (usually "industry sales") specified by the user that will be applied to the regional multipliers. It implies that 1-LPP will be the proportion of the impact event activity that will be imported from outside the economy and have no impact on the local economy.
LPP indicates to the software how much the Event impact should be applied to the Multipliers. The key thing to remember when considering Local Purchase Percentage is that the LPP modifies ONLY the Event values, and it does this BEFORE those values are applied to the Multipliers.
Local Purchase Percentage describes the amount of the Direct Effect that is taking place within the Study Area. If we have properly defined the Study Area, then in most circumstances all the activity we are modeling occurs within our selected geography and thus LPP should be 100%. For example, if we are constructing a building in a county, all the construction activity takes place in that county, even if all the laborers and the requirements for the building are not sourced in the county, so LPP should be 100%. Likewise, if the operations of new or expanded business are occurring entirely inside our county, even if their employment or materials are sourced elsewhere the LPP should be 100% because the business operations themselves are local.