Economists coined the concept of market externality to show that activities in a market affect third parties. An interesting question which economists have left unanswered is whether or not third parties too can affect markets/economy, for there is no concept in economics on how thirdparty activities affect market transactions. This paper therefore explores this issue, using the concept of market internality for this purpose. Four nonmarket activities such as poverty, corruption, political instability, and primary school enrollment are studied to find out if they affect the Nigeria’s non-oil sector. The results showed that the variables have short-run relationships at significant levels.