Purpose: This study has four objectives. First is to investigate and compare the immediate and carryover effects of four pharmaceutical marketing tools (prescriber detailing, medical events, journal ads and direct-to-consumer advertising [DTCA]) on sales. Based on the effect comparisons, the second objective is to determine whether advertising tools that are more compatible with prescriber’s behavior have superior impact on sales. Third is to examine empirical support for the argument that advertising directly to consumers, as a market follower versus leader, has a backfiring effect. Finally, this paper aims to assess the magnitude of variance in sales as a function of each advertising tool. Design/methodology/approach: Data on unit sales and spending (on DTCA, journal ads, events and detailing) ranging 84 months are obtained for six prescription-only cholesterol-reducing brands. First, linearity is checked. Second, evolution versus stationarity is tested by applying the unit-root test. Third, potential endogeneity among variables is assessed with granger causality. Fourth, vector autoregressive model (VAR) that accounts for endogeneity and dynamic interactions is specified. Intercept, seasons and market share are added into the model specification as exogenous variables. Fifth, VAR with akaike selected lags and generalized impulse response are conducted. Finally, sales variance is decomposed with forecast error variance decomposition and Cholesky ordering. Findings: A 10% increase on detailing or journal ads spending brought an immediate (one month) negative effect on sales in a market leader, whereas that same increase is insignificant in a market follower. A 10% increase on DTCA (vs detailing) spending led to a negative (vs positive) carryover effect for the market follower, giving empirical support to the backfiring effect of DTCA and partial evidentiary support suggested about prescriber friendly advertising. However, DTCA induces a larger short term and longer carryover effect in a market leader, with seven times more effect on sales than what detailing does. In addition, it explains 50% of the variation in sales. Originality/value: The model applied captures extensive dynamics; hence, findings are robust. The analysis considered comparison in terms of prescriber friendly (vs not) advertising tools and brand market status and thus can make managers rethink strategy of advertising budget allocations. This study also introduced a new look onto DTCA and hence challenges the traditional thought held on consumer advertising response.
