Welfare impact of climate change on capture fisheries in Vietnam

Since the consumer loss is higher than producer gain, the net social loss occurs, from 3.3 to 4.3 billion USD in 2035 and 4.5 to 8.5 billion USD in 2065. All the currency values are fixed in 2018, in which 1 USD = 7465 VND in PPP (World Bank databank). b < a < 1, i.e., relative demand reduction is less than supply reduction. Aquaculture production is proliferating in Vietnam and worldwide [2]. In both cases where farmed fish has the same or substitute value for wild fish, the expansion of aquaculture shifts consumption from wild to farmed fish. Despite the growing population and improving income, the fishery demand may decrease due to the substitution effect of aquaculture expansion. From Eq (8): P1 P0 ¼ a b � � 1 εS εD > 1 since a > b ! P1 > P0 ð15Þ From both Eqs (10) and (15): CS1 CS0 ¼ a 1 P1þεD 1 P1þεD 0 P1þεD max P1þεD 0 � � < a < 1 ð16Þ Eq (16) indicates that consumers suffer from loss due to a price increase. Table 4. Household’s fishery demand function in Vietnam, 2018. Variable Coefficient Standard Error Fish price (log) -0.1618 ��� 0.0158 Income (log) 0.1263 ��� 0.0107 Pork price (log) 0.2693 ��� 0.0377 Chicken price (log) 0.0683 ��� 0.0179 Household size 0.1405 ��� 0.0061 Red River Delta 0.2964 ��� 0.0237 North Central Coast 0.3296 ��� 0.0409 Central Highlands 0.2899 ��� 0.0303 Southeast 0.5510 ��� 0.0311 Mekong River Delta 0.8005 ��� 0.0354 Coastal provinces 0.3706 ��� 0.0312 Gender of household head -0.4462 ��� 0.0191 Age of household head 0.0021 ��� 0.0006 Marital status household head 0.3723 ��� 0.0225

Years of schooling of household head -0.0206 ��� 0.0018 Agricultural jobs 0.0510 ��� 0.0195 Service jobs 0.0101 0.0197 _cons -0.5427 ��� 0.1984 Weighted Least Square Regression: Dependent variable: Fish consumption quantity (log) n = 8288, Prob(F) = 0.0000, Adjusted R2 = 0.4395 �p < 0.1 ��p < 0.05 ���p < 0.01 https://doi.org/10.1371/journal.pone.0264997.t004 PLOS ONE Welfare impact of climate change on capture fisheries in Vietnam PLOS ONE | https://doi.org/10.1371/journal.pone.0264997 April 25, 2022 12 / 20