Abstract:
Riparian habitats (RH) provide aesthetic beauty, clean water and environment among others. Despite
these values, RH have been threatened and destroyed by effects of human encroachment among others.
RH functioning has been hindered despite various state interventions towards RH protection. The
habitats have continued to act as dumpsites. From literature, no study has valued RH protection in
Kenya. Therefore, this study aimed to carry out economic valuation of RH protection in Nairobi County,
Kenya. Specific study objectives were to determine the effect of changes in: Elicitation Format (EF), Bid
Range (BR), Payment Vehicle (PV) and the Valuation Good (VG) all on valuation estimates. Welfare
economics and utility maximization theories were utilized. Contingent valuation method (CVM) elicited
households‘ willingness to pay (WTP) and its standard deviation (SD). 16 locations were purposively
selected for study and stratified into 2 subsamples based on EF, with each subsample further stratified
into public and private categories.Within these categories, there were six strata each (Trust, Tax, Raised
bid, Lowered bid, Public good, Private good). Stratified proportionate random sampling was used to
sample 1000 households. Cross–sectional survey design and experimental cards (Stochastic payment
card (SPC) and multiple bound discrete choice (MBDC) generated the data. Primary and secondary data
sources were used. Data were collected through structured questionnaires. Two stage random valuation
model aided data analysis. Data were processed in STATA and subjected to Mann- Whitney test (MWT)
and F test statistics. 64% of households were male, older (>38 years) with mean income of KES.
50,444/Month. 71.8% of households attained post college education level and had smaller family sizes
(<4 households) hence found it necessary to protect RH (95%). SPC households expressed lower but
consistent WTP values (KES.925.1±48.3) at (p<0.01; MWT=2.717), indicating that such households
would consistently make their payments towards protection. Change in EF from SPC to MBDC
increased both WTP and its SD by 6.7% and 9.8 % respectively at p<0.01. Raised BR exhibited higher
and consistent WTP (KES.1166.6±1003.3). A finding contrary to economic theory where WTP rise with
reduction in bid amounts. Regression of change in BR on its estimates, increased WTP and reduced SD
respectively by 23.7% and 19.4% at p<0.01. Tax PV showed higher WTP and SD
(KES.1180.93.1±1332.6) at (p<0.1; MWT=1.865), evidence that it does not elicit protest responses as
noted in the literature. The view of RH as public good elicited higher and inconsistent WTP (KES.
1022.1±1318.5) at p>0.01. Regression of change in VG from Private to Public on VG estimates
increased both WTP and SD by 9.9% and 7.9% respectively at p<0.01. Factors: - Age, Distance, income,
Necessity to protect RH, EF, significantly affected valuation estimates. In conclusion, households
expressed positive WTP amounts towards RH protection. The participation of women, youth, and larger
families in protection was limited hence need for sensitization. SPC proved desirable for future valuation
given its understated welfare estimates. Change in BR led to households‘ true valuation of RH
protection. Tax PV was preferred for valuation of RH protection due to the distrust expressed by
households over the Trust fund. Households viewing RH as private expressed confident support for it. It
is suggested that conservationists and natural resource management authorities, such as the Kenya
National Environment Management Authority (NEMA), should focus on increasing the participation of
women, youth, and larger families in RH protection efforts through targeted awareness campaigns.
Incorporating SPC format in future RH valuation studies is essential for ensuring consistency in
households' WTP estimates. Utilization of Lowered BR in future valuation studies could produce more
accurate and motivating WTP estimates, particularly for areas like Karura Forest. County governments
are encouraged to establish a voluntary environmental tax fund for RH protection, ensuring transparency
to build public trust. The study also advocates for using tax preferences as a PV in future valuations of
environmental goods and services. Leasing public RH by the government to private entities for enhanced
protection is also encouraged. Moreover, VG estimates could inform budget and policy proposals for
managing various public RH, with adjustments made to ensure socio-demographic equity. Finally, future
RH protection strategies should be tailored to consider key factors such as age, distance, income, and
perceived necessity, which significantly influence valuation estimates.