The own price elasticity at one level of aggregation can
reflect both the own price and cross price elasticities
at other levels of aggregation. For example, the price
elasticity at the route level is a function of the own
price and cross price elasticities at the price class
and carrier levels of aggregation. The interaction
between these effects adds significant complexity to
the analysis, requiring clarity on which own price and
cross price elasticity were measured and controlled for.
For example, an analysis of route-level elasticities which
does not control for route substitution effects may be
more appropriate for a national-level elasticity