Rural community radio licensing and intergenerational language transmission in Senegalese villages: an instrumental-variable analysis of transmitter-range exposure

Community radio licensing in Senegal has been justified partly as a means of sustaining national languages in rural areas, yet the causal status of the licence-to-language link remains unsettled because transmitter placement is not random with respect to village characteristics. No observational data are used or claimed. Under a declared variance structure with between-cluster SD = 6.0, residual SD = 4.5 and intraclass correlation = 0.64, power was estimated across 2000 design cells spanning cluster counts of 8, 16, 24 and 32 and effects of 3, 5 and 8 percentage points. The design attains 80 per cent power at 54 clusters for a 5-percentage-point effect. The exclusion restriction for transmitter reach is defensible only under explicit settlement-geography assumptions, and that the before-after-control-impact estimator's credibility in this setting depends more on cluster count than on the instrument's strength. The contribution is a design specification for a causal question that has so far been argued qualitatively, together with a calibrated statement of what village-level evidence can and cannot establish.