This paper investigates the extent to which slum notification, a tenure formalization policy that officially recognises settlements as slums and ensures the occupancy rights of the residents, has stimulated housing investment by the households in India. In using a nationally representative data set, propensity score methods are employed to reduce selection bias. This paper finds that given the observed household characteristics adjusted by propensity scores, slum notification will increase the average amount of money spent on housing construction, though the proportion of households who would improve their houses is estimated to be higher in non-formalized settlements. The findings suggest that not only formalizing slums but also supporting self-help efforts by the residents of non-formalized slums would be effective for improving their housing conditions.