Interest organizations across economic sectors: explaining interest group density in the European Union

The number of interest organizations (density) varies across policy
domains, political issues and economic sectors. This shapes the nature and outcomes
of interest representation. In this contribution, we explain the density of interest
organizations per economic sector in the European Union on the basis of political
and economic institutional factors. Focusing on business interest representation,
we show that economic institutions structure the ‘supply’ of interest organizations
by affecting the number of potential constituents, the resources available for lobbying
and the geographical level of collective action of businesses. In contrast, we do not
find consistent evidence that political institutions produce ‘demand’ for interest
organizations by making laws, developing public policy or spending money. This
is in contrast to the extensive evidence that such factors affect lobbying practices.
The European Union interest system is (partially) shaped by economic factors, relatively
independent from public policy or institutions.