An ideologically biased expert faces trade-offs in model design. The perceived model must be autocoherent—its use by all agents delivers a self-confirming equilibrium. Policy may be influenced by manipulating the Keynesian multiplier or the Phillips curve parameters. Ideological bias may arise in a way that resembles well-known historical controversies. A larger reported Keynesian multiplier is favored by more left-wing economists, as is a flatter inflation output trade-off. Some combinations of parameters must be truthfully revealed, illustrating the tight link between parameter identification and the scope for bias that is implied by the autocoherence conditions.
"The Possibility of Ideological Bias in Structural Macroeconomic Models."
American Economic Journal: Macroeconomics,