channels. On the supply side, foreign aid works to reduce the marginal cost to household as well as decrease the cost of provision to governments tat otherwise may not be able to afford to provide the infrastructure.

With the exception of Abell ́an and Alonso (2022), previous research focuses exclusively either on the demand side or the supply side without integrating supply and demand for access to and use of sanitation. We do so in this paper. Second, although some papers have mentioned voice and accountability, they do not focus on it as the central issue in their analyses. Finally, none of these studies establishes the direction of causation between voice and accountability on the one hand and access and use of sanitation on the other. Our paper addresses these issues by investigating the _causal effects_ of _Voice_ on sanitation access and does so within a supply and demand framework. In addition, our study extends the analysis to study rural and urban areas alongside the role of voice and accountability in closing the rural/urban gap in access to sanitation. Besides using instrumental variables estimation to overcome possible endogeneity problems, we also use a novel instrument free estimator in kinky least squares developed by Kiviet (2013, 2022) as a robustness check on our results. Our primary approach in this study is the use of crosssection data and thus does not explicitly account for time dimension. The use of cross sectional data allows us to use our estimation methodology and draw causality in the process.

# 3. CONCEPTUAL FRAMEWORK: DEMAND AND SUPPLY CHANNEL OF VOICE & ACCOUNTABILITY

Access to and use of sanitation services is a two-part problem— a demand side and a supply side issue. In this section, we provide a brief description of the channels through which _Voice_ can directly broaden access to sanitation by stimulating the demand and supply.

On the demand side, households are the main beneficiaries of sanitation services and hence, have the key responsibility of gaining access to it. In low information environments, lack of awareness of the benefits of sanitation as well as government’s inability or unwillingness to provide sanitation services can lower the demand for these services by households. The lack of information issue is likely to be more pervasive in rural areas compared to urban areas. Notice that when the freedom of the media is suppressed by government, certain socioeconomic issues may not be publicly discussed and certain educative information may not reach the populace. In contrast, a free media can effectively serve as a medium in communicating key information to citizens on the benefits of sanitation. Consequently, by providing the appropriate health information and education about the benefits of sanitation through TV and radio advertisements for example, _Voice_ can stimulate the demand for sanitation, all things equal.

Formally, we can consider that households maximize a utility function that is positive and concave in sanitation services and a bundle of all other consumption goods and services ( _X_ ) subject to budget constraints. Additionally, we assume that households gain utility from an exogenous level of _Voice v_ in the country that is complementary to sanitation services. Specifically, voice increases the marginal utility of sanitation and hence, the demand for sanitation. Algebraically, the household utility is given as _U_ = _u_ ( _s, X, v_ ) _, ∂U/∂ s >_ 0 and _∂U/∂ s∂ v >_ 0. The last term captures the complementarity (in the Edgeworth pareto sense) between voice and sanitation services in utility, so that an improvement in voice and accountability raise the marginal utility of sanitation services and hence, its demand. We can summarize the demand function for sanitation service as _s_<sup>_d_</sup> = _g_ ( _v, Z_ ), where _Z_ captures other factors that may affect the demand for sanitation and _∂ s_<sup>_d_</sup> _/∂ v >_ 0.<sup>8</sup>

> 8Other factors such as lack of basic income and credit constraints can reduce demand for the adoption of safely managed sanitation services. Indeed, credit constraints often limits poor households in the adoption of privately optimal technology (e.g., flushable toilets or energy efficient technologies) that can improve household lifestyle. See for instance, Berkouwer and Dean (2022) for the case of adoption of energy efficient

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