This article intends to contribute to the analyses of the effects of public policies on innovation at the firm level, based on the case of a small developing economy (Uruguay). It studies the relation between public support and the probability of innovating at the market level, introducing a lag between support and innovation. The econometric analysis uses binomial Probit models with Heckman sampling bias correction. The article concludes that public support matters for innovation at the market level, whether by stimulating innovation or by facilitating it in already innovative firms.  Moreover, the innovation activities of Uruguayan firms receiving public support do not seem to require a long time to develop. Finally, it is suggested that the relation between firm internationalization and the probability of innovating be further studied. Resumen: Este artículo pretende aportar a la literatura que analiza los efectos de las políticas públicas sobre la innovación a nivel de firmas, a partir del caso de una pequeña economía en desarrollo, Uruguay. Analiza la relación entre apoyo público y probabilidad de innovar para el mercado, e introduce un rezago entre el apoyo otorgado y la innovación realizada, de manera de valorar rezago en el impacto. El análisis econométrico utiliza Probit binomiales con corrección de Heckman, para corregir sesgos de selección. Se concluye que los apoyos públicos importan a los efectos de innovar para el mercado, ya sea porque estimulan la innovación o porque la facilitan en empresas que ya innovan. Asimismo, las actividades de innovación de empresas asociadas a apoyos públicos, en Uruguay, no parecen requerir de largo tiempo de maduración. Finalmente, se sugiere profundizar el estudio de la relación entre internacionalización de las empresas y probabilidad de innovar. Palabras claves: innovación, subsidios, evaluación de política.Title: Public support and innovation at the firm levelThis article intends to contribute to the analyses of the effects of public policies on innovation at the firm level, based on the case of a small developing economy (Uruguay). It studies the relation between public support and the probability of innovating at the market level, introducing a lag between support and innovation. The econometric analysis uses binomial Probit models with Heckman sampling bias correction. The article concludes that public support matters for innovation at the market level, whether by stimulating innovation or by facilitating it in already innovative firms. Moreover, the innovation activities of Uruguayan firms receiving public support do not seem to require a long time to develop. Finally, it is suggested that the relation between firm internationalization and the probability of innovating be further studied. Keywords: innovation, subsidies, policy evaluation.