# RECORD e2cefa2df09279ce534acb1e9e0f5991e38a2e5f # TITLE: Heterogeneous Individual Valuations of a Mild Climate # YEAR: 2026.0 VENUE: Environmental and Resource Economics DOI: 10.1007/s10640-026-01110-4 # AUTHORS: Jan K. Brueckner # PAGES: 23 CANDIDATE TABLE PAGES (1-based): [10, 12, 13, 16, 17, 19] # ABSTRACT: This paper explores heterogeneous individual valuations of an important amenity, climate mildness, using a traditional Rosen-Roback empirical framework. It does so by including interaction terms between the amenity and worker characteristics in an hedonic wage regression that also includes a housing-price measure. The results suggest that non-young workers (those in the mid-age and old groups) value a mild climate more than do young workers, matching the usual view that the tolerance for cold weather declines with age. The findings also suggest that, like their highly educated counterparts, workers with low education levels also highly value a mild climate, with workers in the middle range of education having a lower valuation. These findings, which contradict the view that only better-off individuals care about amenities, could reflect the lower burden in mild weather of the manual work done by the less educated. In addition to presenting these empirical findings, the paper further contributes by presenting new analytics for the Rosen-Roback model in a setting with individual heterogeneity. ===== PAGE 1 (score 6, numeric-paren 0, table-words 0, var-words 6) ===== Environmental and Resource Economics (2026) 89:59 https://doi.org/10.1007/s10640-026-01110-4 Heterogeneous Individual Valuations of a Mild Climate Jan Brueckner1 Received: 20 January 2026 / Revised: 12 June 2026 / Accepted: 31 July 2026 / Published online: 17 August 2026 © The Author(s) 2026 Abstract This paper explores heterogeneous individual valuations of an important amenity, climate mildness, using a traditional Rosen-Roback empirical framework. It does so by includ­ ing interaction terms between the amenity and worker characteristics in an hedonic wage regression that also includes a housing-price measure. The results suggest that non-young workers (those in the mid-age and old groups) value a mild climate more than do young workers, matching the usual view that the tolerance for cold weather declines with age. The findings also suggest that, like their highly educated counterparts, workers with low education levels also highly value a mild climate, with workers in the middle range of education having a lower valuation. These findings, which contradict the view that only better-off individuals care about amenities, could reflect the lower burden in mild weather of the manual work done by the less educated. In addition to presenting these empirical findings, the paper further contributes by presenting new analytics for the Rosen-Roback model in a setting with individual heterogeneity. Keywords  Valuation of amenities · Climate mildness · Hedonic wage regression 1  Introduction The pioneering work of Rosen (1979) and Roback (1982) provided a theoretical framework for predicting the effect of amenities on wages and real-estate prices, and their approach has influenced all subsequent work in this area. In their framework, a city’s amenities enter both the worker’s indirect utility function and the firm’s cost function, both of which also depend on the local wage (a cost to the firm) and the price of real estate, which is an input for the firm as well as a consumption good for the worker. For the equilibrium requirements of spatially uniform utilities and production costs to be satisfied, wages and real-estate prices must vary with city amenity levels in a particular fashion. The required variation is ambigu­ Jan Brueckner jkbrueck@uci.edu 1 Department of Economics, UC Irvine, Irvine, CA 92697, USA ===== PAGE 10 (score 18, numeric-paren 0, table-words 5, var-words 5) ===== 1 3 59  Page 10 of 23 J. Brueckner ness largely dependent on region, such controls would remove much of the variation in mildness that identifies individual valuations of this amenity. Table 1 shows summary statistics for the sample, with the inline-eq-IEq103 variable being de- meaned, yielding a zero mean. As can be seen, the mean hourly wage is $15.63, with the minimum equal to the federal minimum wage of $5.15 and a maximum of $293.27. Slightly more than half the workers are male, 8.9% are black, 13.7% are hispanic, and the shares of the education groups decline slightly as education rises. The young and mid-age groups are similar in size, but only 8.5% of workers are in the old group. Being omitted from the regression tables, the year and marital-status variables’ statistics are not shown in Table 1, but the observations are very evenly split across the five sample years, and the most common marital statuses are married with civilian spouse present (54.0%), never married (29.0%), and divorced (10.7%). 3.2  Empirical Model To write the regression equations in compact form, let inline-eq-IEq116 and inlin e - eq -I Eq117 denote the three age (inline-eq-IEq118, inline-eq-IEq119, inline-eq-IEq120) and education dummies (inline-eq-IEq121, inline-eq-IEq122, inline-eq-IEq123) respectively. The standard unconditional wage regression includes individual characteristics in uninteracted form but not the housing-cost variable. Using inline-eq-IEq124 as the observation index, the regression equation is written Table 1  Summary statistics Variable Mean Std. Dev. Min Max Wage ($/hr) 15.63 10.93 5.15 293.27 Houscost (CMSA index) 0.052 0.251 −0.544 0.783 Mildness 0 12.03 −28.76 21.38 Low_ed 0.409 0.492 0 1 Mid_ed 0.307 0.461 0 1 High_ed 0.284 0.451 0 1 Young 0.440 0.496 0 1 Mid_age 0.476 0.499 0 1 Old 0.085 0.279 0 1 Male 0.509 0.500 0 1 Black 0.089 0.279 0 1 Hispanic 0.137 0.344 0 1 Observations = 257,478 across 219 MSAs Variable Definitions inline-eq-IEq320 is a CMSA-specific index equal to the intercept from a detailed hedonic housing price regression. inline-eq-IEq321 measures annual month-level deviations from a temperature of 20 degrees Celsius at the MSA level. inline-eq-IEq322 is a dummy variable indicating that the worker has a high-school degree or less. inline-eq-IEq104 is a dummy indicating that the worker has some college or a junior-college degree. inline-eq-IEq324 is a dummy indicating that the worker has a college degree or a post-graduate degree. inline-eq-IEq325 is a dummy indicating that the worker’s age is less than 35 years. inline-eq-IEq326 is a dummy indicating that the worker’s age is at least 35 but less than 55 years. inline-eq-IEq327 is a dummy indicating that the worker’s age is at least 55 years. ===== PAGE 11 (score 15, numeric-paren 0, table-words 6, var-words 3) ===== 1 3 Page 11 of 23  59 Heterogeneous Individual Valuations of a Mild Climate displ a y - e q-Equ12  (12) where inline-eq-IEq125 is the error term, inli ne-eq-IEq126 and inl ine-eq-IEq127 are dropped to avoid collinearity, and inline-eq-IEq128 is the vec­ tor of control variables (inline-eq-IEq129, inline-eq-IEq130, inline-eq-IEq131, marital status, SIC shares, and year dum­ mies). The conditional form of the standard regression comes from adding inline-eq-IEq132 as a covariate in (12). In (12), the inline-eq-IEq133 coefficient captures the average valuation of climate mildness across all workers, while the inline-eq-IEq134 and inline-eq-IEq135 coefficients for i n li ne-eq-IEq136 capture the wage effect of education relative to inline-eq-IEq137 group and the wage effect of age relative to the inline-eq-IEq138 category. Since education and age are expected to raise wages, these four coefficients are expected to be positive and larger for i n line-eq-IEq139 than for i n line-eq-IEq140. When interactions between inline-eq-IEq141 and the age and education variables are intro­ duced, the unconditional wage regression becomes displ a y -eq-Equ1 3  (13) where one of the age interactions is dropped to avoid collinearity. To get the condi­ tional version of the interaction regression, inline-eq-IEq142 is added as a covariate in (13). The inline-e q -IEq143 interaction variables allow the wage effect of climate mildness to vary across all three of the education groups (i n li ne -eq-IEq144), while the inline-e q -IEq145 coefficients allow the mildness effect to vary across all three of the age groups. Note that, with mildness not appearing in uninteracted form, there is no baseline effect of inline-eq-IEq146, allowing each group to have its own interaction coefficient without creating multicollinearity. A nega­ tive coefficient for an interaction variable, say inline-e q -IEq 1 47 , implies that greater climate mildness reduces the wage for members of the inline-eq-IEq148 group, and similarly for the other interaction coefficients. Note that this negative coefficient also implies that the wage gain relative to the inline-eq-IEq149 group from being in the inline-eq-IEq150 group is smaller when climate mildness is high than when it is low, a consequence of the depressing wage effect of mildness for the inline-eq-IEq151 group. 4  Empirical Results The estimated hedonic wage regressions are shown in Tables 2–3. Table 2 shows a Rosen- Roback wage regression with a standard treatment of amenities, where the inline-eq-IEq152 variable appears only in level form. Table 3 adds interactions between inline-eq-IEq153 and edu­ cation and between inline-eq-IEq154 and age. The various columns in the tables show a condi­ tional regression (which directly gives amenity valuations) along with the corresponding unconditional regression (where inline-eq-IEq155 is dropped), with the theory used to motivate comparisons between the two regressions. All of the regressions are weighted by the CPS ===== PAGE 12 (score 62, numeric-paren 36, table-words 8, var-words 6) ===== 1 3 59  Page 12 of 23 J. Brueckner wage-representativeness variable, inline-eq-IEq156, ensuring that the observations reflect the overall population.8 Standard errors are clustered at the MSA level. Since no complications are present in the estimation, the regressions use ordinary-least-squares. 4.1  Standard Regressions Column 1 of Table 2 shows the conditional version of a standard hedonic wage regression, with inline-eq-IEq169 appearing on the right-hand side. This variable’s coefficient is significantly positive, indicating that wages are higher in high housing-cost areas. Recall that the coef­ ficient of inline-eq-IEq170, which appears only in level form, directly reveals (in absolute value) the average valuation of the amenity across all workers, given the presence of inline-eq-IEq171 (see (4)). The coefficient is negative and statistically significant, as expected, indicating that workers will accept a lower wage to live and work in a milder climate. Column 2 of Table 2 drops the inline-eq-IEq172 variable, yielding an unconditional wage regres­ sion. While the inline-eq-IEq173 coefficient is still negative and significant, it increases in absolute value relative to column 1, rather than decreasing, as predicted by the theory.9 This pattern persists through the results below that use inline-eq-IEq174 interactions instead of the variable’s level, along with the CMSA-level inline-eq-IEq175. A possible explanation is that this inline-eq-IEq176 variable is correlated with some unobserved MSA-level determinants of wages (e.g., high 8 To be safe, these weights are still applied even though the exclusions described themselves alter the repre­ sentativeness of the sample. 9 Since the coefficients come from different regressions, a formal test for equality is not possible. VARIABLES (1) lwage (2) lwage Mildness −0.00202** −0.00227** (0.000326) (0.000454) Houscost 0.225** – (0.0229) Mid_edx 0.215** 0.218** (0.0106) (0.0104) High_edx 0.607** 0.611** (0.0136) (0.0134) Mid_age 0.165** 0.166** (0.00412) (0.00428) Old 0.125** 0.126** (0.00771) (0.00769) Male 0.187** 0.187** (0.0108) (0.0107) Black −0.127** −0.130** (0.00766) (0.00754) Hispanic −0.241** −0.240** (0.0163) (0.0165) Constant −0.385 1.694 (1.035) (1.550) Observations 257,478 257,478 inline-eq-IEq157 0.431 0.426 Table 2  Standard Rosen-Roback hedonic wage regressions Standard errors clustered at the metro level in parentheses ** pinline-eq-IEq1580.01, * pinline-eq-IEq1590.05 Marital-status, SIC employment-share, and year coefficients not reported ===== PAGE 13 (score 158, numeric-paren 132, table-words 3, var-words 5) ===== 1 3 Page 13 of 23  59 Heterogeneous Individual Valuations of a Mild Climate worker productivity in high-cost San Francisco), which prevent the expected drop of the inline-eq-IEq177 coefficient when inline-eq-IEq178 is removed from the regression. As will be seen below, the expected pattern emerges using the state-level version of inline-eq-IEq179, which may be less correlated with these unobservables. Turning to the dummy control variables, inline-eq-IEq180 and inline-eq-IEq181 are dropped, so that the default worker is a young, female married to a civilian husband (the default marital status) with low education and a non-Black, non-Hispanic race. The wage effects of the dummy variables are as expected. More education or a non-young age raises the wage, with the point estimate of the age effect slightly smaller for old workers. Male wages are higher Table 3  Hedonic wage regressions with amenity interactions VARIABLES (1) lwage (2) lwage (3) lwage (4) lwage (5) lwage (6) lwage Houscost 0.223** – 0.224** – 0.222** – (0.0227) (0.0229) (0.0227) Mid_ed 0.203** 0.204** 0.215** 0.218** 0.203** 0.204** (0.00618) (0.00611) (0.0105) (0.0103) (0.00620) (0.00612) High_ed 0.601** 0.604** 0.607** 0.612** 0.600** 0.604** (0.0125) (0.0123) (0.0136) (0.0134) (0.0125) (0.0123) Mid_age 0.165** 0.166** 0.172** 0.173** 0.172** 0.173** (0.00412) (0.00427) (0.00395) (0.00403) (0.00396) (0.00404) Old 0.124** 0.125** 0.128** 0.130** 0.127** 0.128** (0.00756) (0.00755) (0.00754) (0.00752) (0.00717) (0.00716) Mildness inline-eq-IEq160 low_ed −0.00322** −0.00358** – – −0.00258** −0.00292** (0.000648) (0.000684) (0.000594) (0.000613) Mildness inline-eq-IEq161 mid_ed −0.000728 −0.000902 – – −9.10e-05 −0.000245 (0.000426) (0.000515) (0.000505) (0.000545) Mildness inline-eq-IEq162 high_ed −0.00181** −0.00200** – – −0.00106 −0.00123 (0.000607) (0.000680) (0.000699) (0.000728) Mildness inline-eq-IEq163 young – – −0.00134** −0.00158** – – (0.000364) (0.000440) Mildness inline-eq-IEq164 mid_age – – −0.00263** −0.00290** −0.00130** −0.00134** (0.000380) (0.000519) (0.000379) (0.000378) Mildness inline-eq-IEq165 old – – −0.00198** −0.00225** −0.000509 −0.000539 (0.000592) (0.000722) (0.000585) (0.000599) Male 0.188** 0.187** 0.187** 0.187** 0.188** 0.187** (0.0107) (0.0105) (0.0108) (0.0106) (0.0106) (0.0105) Black −0.127** −0.130** −0.127** −0.130** −0.127** −0.130** (0.00747) (0.00730) (0.00771) (0.00759) (0.00752) (0.00734) Hispanic −0.236** −0.235** −0.242** −0.241** −0.237** −0.235** (0.0137) (0.0140) (0.0165) (0.0166) (0.0138) (0.0140) Constant −0.374 1.686 −0.372 1.704 −0.359 1.699 (1.031) (1.546) (1.040) (1.553) (1.036) (1.549) Observations 257,478 257,478 257,478 257,478 257,478 257,478 inline-eq-IEq166 0.431 0.427 0.431 0.426 0.431 0.427 Standard errors clustered at metro level in parentheses ** pinline-eq-IEq1670.01, * pinline-eq-IEq1680.05 Marital-status, SIC employment-share, and year coefficients not reported. ===== PAGE 14 (score 15, numeric-paren 0, table-words 4, var-words 7) ===== 1 3 59  Page 14 of 23 J. Brueckner than those of females, and Black and Hispanic workers earn less than workers outside these groups. All these coefficients are strongly statistically significant.10 4.2  Regressions with Amenity Interactions Table 3 introduces amenity interactions with the three education dummies and the age dum­ mies. Only education interactions are present in columns 1 and 2, with columns 3 and 4 con­ taining only age interactions. Columns 5 and 6 contain both types of interactions. The first column within each pair shows the conditional regression, and the second column shows the unconditional regression. In all the regressions, the inline-eq-IEq182 variable only appears in interacted form, not as a level variable. In the conditional regression in column 1, which includes inline-eq-IEq183, coefficients for two of the inline-eq-IEq184 interaction variables, inline-e q -IEq185 and inline-e q -IEq186, are negative and significant. However, the inline-e q -IEq187 coefficient, while negative, is insignificant and its absolute magnitude is smaller than those of the other two coefficients while being separately statistically unequal to each of them. The hypothesis that all three interaction coefficients are equal is also rejected. The results thus suggest that workers in both the high- and low-education groups value a mild climate, while workers in the middle range of education (high school with some college or an associate degree) have a lower and perhaps zero valuation of climate mildness. While well-educated, and thus well-off, households are often thought to value amenities highly (see for example, Brueckner et al. (1999)), the presence of a similar valuation among the least-educated workers is noteworthy. A possible explanation is that workers with no more than a high-school education are frequently employed in jobs that require manual labor, which often occurs outside rather than indoors. As a result, climate mildness may make the jobs of such workers easier, accounting for their valuation of mildness. While the best-educated workers may have ample leisure time to enjoy outdoor activities, which could contribute to their valuation of climate mildness, the apparent lower valuation for workers in the middle range of education is somewhat puzzling. Conceivably, compared to the least- educated, fewer of these workers may hold manual jobs, while their lower earning power relative to the most-educated may mean longer work hours and less time for outdoor activi­ ties, thereby reducing the middle-range group’s valuation of climate mildness. Climate-mildness valuation by the least educated workers but not by the inline-eq-IEq188 group also raises another issue related to the premises of the Rosen-Roback model. That model is based on the assumption that all workers are mobile across regions, and one may wonder whether this assumption is accurate for low-education workers, for whom moving costs may be unaffordable. While this observation may cast doubt on the applicability of the model to this group, it could be argued that everyone is mobile in a sufficiently long-run context, even workers with low resources. Turning to the unconditional regression in column 2 of Table 3, the coefficients of the inline-eq-IEq189 interactions with inline-eq-IEq190 and inline-eq-IEq191 remain negative and significant. The coefficients are larger in absolute value than those in column 1, following the unexpected pattern in Table 2. 10 The omitted marital-status category is the most common one, married with civilian spouse present, and the dummy coefficients for the other categories are all negative, indicating higher wages in typical married households. ===== PAGE 16 (score 86, numeric-paren 36, table-words 19, var-words 8) ===== 1 3 59  Page 16 of 23 J. Brueckner Table 4 shows the traditional wage regressions, and in the conditional version shown in column 1, the inline-eq-IEq229 coefficient increases in absolute value, being now larger than the coefficient in column 2, which is unchanged. This is the pattern predicted by the theory, with the required compensating decline in the wage as inline-eq-IEq230 increases being smaller when inline-eq-IEq231 exerts its own separate utility-equalizing force (rising with inline-eq-IEq232) rather being held fixed. The other estimates in Table 4 are similar to those in Table 3. As in Table 3, the interaction regression in column 1 of Table 5 again suggests that work­ ers with low and high education levels value climate mildness more than do workers with education in the middle range. While again larger in absolute value, the inline-e q -IEq233 and inline-e q -IEq234 coefficients are also again both statistically different from the inline-eq-IEq235 interaction coefficient. The latter coefficient, however, is now also statistically sig­ nificant. Note that the column-1 interaction coefficients are now larger in absolute value than the unconditional column-2 coefficients, as predicted by the theory. As in Table 3, all the age interaction coefficients in column 3 of Table 5 are negative and significant, with the inline-eq-IEq236 and inline-eq-IEq237 interaction coefficients again larger in absolute value than the inline-eq-IEq238 interaction coefficient. As before, the difference is statistically significant only for the inline-eq-IEq239 interaction coefficient. As predicted by the theory, the column 3 interaction coefficients are now larger in absolute value than the unconditional coefficients in column 4. Turning to columns 5–6 of Table 5, the inline-e q -IEq240 coefficient in column 5 now retains the statistical significance seen in column 1, with the inline-e q -IEq241 coefficient losing it. That coefficient is again statistically different from the other two, VARIABLES (1) lwage (2) lwage Mildness −0.00252** −0.00227** (0.000436) (0.000454) Houscost 0.0135** – (0.00318) Mid_ed 0.216** 0.218** (0.0105) (0.0104) High_ed 0.611** 0.611** (0.0134) (0.0134) Mid_age 0.166** 0.166** (0.00418) (0.00428) Old 0.125** 0.126** (0.00774) (0.00769) Male 0.187** 0.187** (0.0107) (0.0107) Black −0.126** −0.130** (0.00748) (0.00754) Hispanic −0.241** −0.240** (0.0162) (0.0165) Constant −1.253 1.694 (1.731) (1.550) Observations 257,478 257,478 inline-eq-IEq217 0.428 0.426 Table 4  Standard Rosen-Roback hedonic wage regressions with state-level housing cost Standard errors clustered at the metro level in parentheses **pinline-eq-IEq2180.01, * pinline-eq-IEq2190.05 Marital-status, SIC employment-share, and year coefficients not reported. ===== PAGE 17 (score 168, numeric-paren 134, table-words 6, var-words 7) ===== 1 3 Page 17 of 23  59 Heterogeneous Individual Valuations of a Mild Climate implying that workers in the middle education range have a lower mildness valuation than the other education groups. Column 5’s age interaction coefficients show the same pattern as in Table 3. Note that, while column 5’s education interaction coefficients are now larger than those in column 6, as predicted, that relationship does not hold for the age interaction coefficients. While mostly matching the theoretical prediction regarding conditional vs. unconditional coefficient magnitudes, the results in Table 5 also reaffirm the conclusions from Table 3. They suggest that workers with high and low education levels value climate mildness by Table 5  Hedonic wage regressions with amenity interactions and state-level housing cost VARIABLES (1) lwage (2) lwage (3) lwage (4) lwage (5) lwage (6) lwage Houscost 0.0133** – 0.0135** – 0.0133** – (0.00316) (0.00318) (0.00316) Mid_ed 0.203** 0.204** 0.216** 0.218** 0.203** 0.204** (0.00618) (0.00611) (0.0105) (0.0103) (0.00619) (0.00612) High_ed 0.604** 0.604** 0.611** 0.612** 0.603** 0.604** (0.0123) (0.0123) (0.0134) (0.0134) (0.0123) (0.0123) Mid_age 0.166** 0.166** 0.173** 0.173** 0.172** 0.173** (0.00418) (0.00427) (0.00401) (0.00403) (0.00402) (0.00404) Old 0.125** 0.125** 0.129** 0.130** 0.128** 0.128** (0.00759) (0.00755) (0.00761) (0.00752) (0.00725) (0.00716) Mildness inline-eq-IEq220 low_ed −0.00378** −0.00358** – – −0.00312** −0.00292** (0.000706) (0.000684) (0.000649) (0.000613) Mildness inline-eq-IEq221 mid_ed −0.00118* −0.000902 – – −0.000532 −0.000245 (0.000489) (0.000515) (0.000545) (0.000545) Mildness inline-eq-IEq222 high_ed −0.00228** −0.00200** – – −0.00152* −0.00123 (0.000662) (0.000680) (0.000732) (0.000728) Mildness inline-eq-IEq223 young – – −0.00184** −0.00158** – – (0.000448) (0.000440) Mildness inline-eq-IEq224 mid_age – – −0.00314** −0.00290** −0.00132** −0.00134** (0.000493) (0.000519) (0.000378) (0.000378) Mildness inline-eq-IEq225 old – – −0.00248** −0.00225** −0.000510 −0.000539 (0.000656) (0.000722) (0.000586) (0.000599) Male 0.187** 0.187** 0.187** 0.187** 0.187** 0.187** (0.0106) (0.0105) (0.0107) (0.0106) (0.0106) (0.0105) Black −0.126** −0.130** −0.126** −0.130** −0.126** −0.130** (0.00727) (0.00730) (0.00753) (0.00759) (0.00732) (0.00734) Hispanic −0.236** −0.235** −0.242** −0.241** −0.237** −0.235** (0.0136) (0.0140) (0.0163) (0.0166) (0.0137) (0.0140) Constant −1.216 1.686 −1.237 1.704 −1.197 1.699 (1.727) (1.546) (1.735) (1.553) (1.731) (1.549) Observations 257,478 257,478 257,478 257,478 257,478 257,478 inline-eq-IEq226 0.428 0.427 0.428 0.426 0.428 0.427 Standard errors clustered at metro level in parentheses ** pinline-eq-IEq2270.01, * pinline-eq-IEq2280.05 Marital-status, SIC employment-share, and year coefficients not reported. ===== PAGE 18 (score 36, numeric-paren 0, table-words 15, var-words 6) ===== 1 3 59  Page 18 of 23 J. Brueckner more than workers with moderate education levels, and that young workers value climate mildness less than non-young workers. 4.4  Further Connections to the Theory While Tables 4 and 5 show the predicted theoretical relationship between the coefficient magnitudes in the conditional and unconditional regressions, the analysis in Sect. 2 offers some further guidance in appraising the results. In particular, recall that the theory shows how differences in housing demands and amenity valuations between the two posited worker types can affect the magnitudes of the unconditional amenity wage effects for the types. Consider the unconditional regression in column 2 of Table 3, which pertains to the three education groups. While the regression has three groups rather than the two worker types in the model, pairwise comparisons can be made between the interaction coefficients using the theory, carrying out a inline-eq-IEq242/inline-eq-IEq243 comparison and a separate inline-eq-IEq244/inline-eq-IEq245 comparison, relying on the effectively zero value for the inline-eq-IEq246 interaction coefficient.12 Consider first the inline-eq-IEq257/inline-eq-IEq258 comparison. Relative to the inline-eq-IEq259 group (type 2 in the theory), the inline-eq-IEq260 group (type 1) has a higher mildness valuation given the results of column 1 in Table 3, with inline-eq-IEq261 . But given its lower income, housing demand should also be lower for the inline-eq-IEq262 group, implying inlin e -eq-IEq263. From above, these two inequali­ ties together yield a negative unconditional type-1 (inline-eq-IEq264) wage effect in eq (8) along with an ambiguous (possibly zero) sign for the type-2 (inline-eq-IEq265) effect in (9), matching the results in column 2 of Table 3. For the inline-eq-IEq266/inline-eq-IEq267 comparison, the higher income of the inline-eq-IEq268 group (now type 1) should make inlin e -eq-IEq269 (type 2 is again the inline-eq-IEq270 group). The greater inline-eq-IEq271 mildness valuation from the unconditional regression means inline-eq-IEq272 , but if the valu­ ation of amenities rises faster than housing demand as income increases (the Brueckner- Thisse-Zenou assumption), then inlin e -eq-I E q273. The conditional type-1 (inline-eq-IEq274) wage effect in (8) is then again negative while the type-2 (inline-eq-IEq275) effect is ambiguous and possibly zero, as in column 2 of Table 3. 4.5  Robustness Check: Stratified Regressions One could argue that, if the goal is to explore the effect of education and age on the valu­ ation of climate mildness, a different and possibly better approach is to estimate regres­ sions stratified by worker category instead of a pooled regression with interaction variables. Accordingly, as a robustness check, this section replaces the regressions using inline-eq-IEq276 interaction variables with stratified regressions. In other words, the single regression with inline-eq-IEq277-education interactions in column 1 of Table 3 is replaced by three separate 12 This exercise is justifiable because deleting the inline-eq-IEq247 and alternatively inline-eq-IEq248 observations from the regression, leaving only two groups, yields the same coefficient pattern as seen in column 2: negative (zero) inline-eq-IEq249 (inline-eq-IEq250) interaction coefficients in the regression containing only inline-eq-IEq251 and inline-eq-IEq252 observations; negative (zero) inline-eq-IEq253 (inline-eq-IEq254) interaction coefficients in the regression containing only inline-eq-IEq255 and inline-eq-IEq256 observations. inline-eq-IEq2247 and alternatively inline-eq-IEq2484 observations from the regression, leaving only two groups, yields the same coefficient pattern as seen in column 2: negative (zero) inline-eq-IEq2459 (inline-eq-IEq2550) interaction coefficients in the regression containing only inline-eq-IEq2251 and inline-eq-IEq2572 observations; negative (zero) inline-eq-IEq2953(inline-eq-IEq2584) interaction coefficients in the regression containing only inline-eq-IEq1255 and inline-eq-IEq2456 observations. ===== PAGE 19 (score 98, numeric-paren 72, table-words 5, var-words 8) ===== 1 3 Page 19 of 23  59 Heterogeneous Individual Valuations of a Mild Climate regressions, one for each education category, with inline-eq-IEq278 appearing in level form in each regression. A comparison of the inline-eq-IEq279 coefficients across the three regressions provides a different way gauging how valuation of the amenity changes across individuals in the different education categories. Similarly, the single regression with inline-eq-IEq280-age interactions in column 3 of Table 3 is replaced by three separate regressions, one for each age category, with inline-eq-IEq281 again appearing in level form. This approach follows Hoch and Drake (1974), who used the stratified approach to investigate how the effect of climate amenities on wages varies across occupations. In contrast to the interaction approach, which implicitly constrains the coefficients of the control variables to be the same across education or age groups, the use of separate regres­ sions under the stratified approach allows these coefficients to differ across groups. If the conclusions generated by the interaction approach also emerge under the less-restrictive stratified approach, then robustness is demonstrated. However, a limitation of the stratified approach is the inability to carry out statistical tests comparing the inline-eq-IEq282 coefficients across groups, which arises because the coefficients come from different regressions instead of common pooled regression. The results of the stratified approach are shown in Table 6, with columns 1–3 showing regressions stratified by education and columns 4–6 showing regressions stratified by age.13 The table uses the CMSA-level housing cost variable. As can be seen, all of the inline-eq-IEq283 coefficients are significantly negative, suggesting that all the education and age groups value 13 Note that, to conveniently evaluate education and age effects under the stratified approach, age is omitted from the stratified education regressions and education is omitted from the stratified age regressions. The alternative would be to run nine different regressions, one for each education-age combination, and to make comparisons across them. Table 6  Stratified wage regressions VARIABLES (1) lwage low_ed = 1 (2) lwage mid_ed = 1 (3) lwage high_ed = 1 (4) lwage young = 1 (5) lwage mid_age = 1 (6) lwage old = 1 Houscost 0.230** 0.276** 0.275** 0.294** 0.326** 0.302** (0.00758) (0.00986) (0.0125) (0.00852) (0.00948) (0.0235) Mildness −0.00259** −0.00104** −0.000994** −0.00232** −0.00259** −0.00165** (0.000120) (0.000154) (0.000194) (0.000134) (0.000149) (0.000373) Male 0.188** 0.175** 0.244** 0.129** 0.272** 0.334** (0.00234) (0.00310) (0.00384) (0.00264) (0.00294) (0.00747) Black −0.120** −0.118** −0.133** −0.148** −0.265** −0.250** (0.00388) (0.00520) (0.00853) (0.00450) (0.00537) (0.0145) Hispanic −0.253** −0.173** −0.265** −0.325** −0.470** −0.436** (0.00311) (0.00552) (0.00918) (0.00374) (0.00491) (0.0144) Constant −1.182* −3.114** −6.871** −2.062** −3.203** −3.679* (0.500) (0.747) (1.362) (0.627) (0.746) (1.868) Observations 105,180 79,128 73,170 113,165 122,466 21,847 inline-eq-IEq284 0.224 0.220 0.159 0.223 0.215 0.201 Standard errors clustered at metro level in parentheses ** pinline-eq-IEq2850.01, * pinline-eq-IEq2860.05 Marital-status, SIC employment-share, and year coefficients not reported. ===== PAGE 20 (score 23, numeric-paren 0, table-words 10, var-words 3) ===== 1 3 59  Page 20 of 23 J. Brueckner climate mildness. However, the patterns seen in the interaction regressions are only partly evident in Table 6. If the education-interaction coefficient pattern were repeated in Table 6, then the inline-eq-IEq287 coefficients in columns 1 and 3 would both be larger in absolute value than the mildness coefficient in column 2. Instead, the inline-eq-IEq288 coefficients in the inline-eq-IEq289 and inline-eq-IEq290 regressions of column 2 and 3 are almost exactly the same size, with absolute values less than half that of the inline-eq-IEq291 coefficient in the inline-eq-IEq292 regression of column 1. The implication is that workers with low education levels appear to value a mild climate more than workers in the two other groups. This conclusion at least preserves the previous finding that low-education workers highly value climate mildness, but it does not show highly educated workers joining in this high valuation. As noted above, however, it is not possible to test for significant differences among the estimated coefficients since they come from different regressions. Thus, for example, tests for whether the inline-eq-IEq293 coefficients in the inline-eq-IEq294 and inline-eq-IEq295 regressions are statisti­ cally equal or whether they differ individually from the inline-eq-IEq296 coefficient are not possible, which means that the claim above of a higher mildness valuation for the inline-eq-IEq297 group cannot be rigorously justified. This inability represents a major limitation of the stratified approach. Columns 4–6 of Table 6 show similar valuations of climate mildness in the inline-eq-IEq298 and inline-eq-IEq299 groups, but a lower valuation for older workers. Therefore the previous conclu­ sion that non-young workers value climate mildness more than the young is not replicated. These differences in results come from not constraining the control-variable coefficients to be the same across groups, the consequences of which can be seen in the variation in these coefficients across the regressions in Table 6. For example, the wage effect from being male is considerably larger for mid-age workers than for low-education workers (compare col­ umns 5 and 1 of Table 6). One could argue that, if the goal is to compare amenity valuations across groups, then giving gender and race effects the same freedom to vary across groups prevents drawing the sharp conclusions that are sought, a problem that is compounded by the inability to carry out comparative tests. On the other hand, allowing flexibility in the control coefficients may end up giving a truer picture of amenity valuations. For the cur­ rent exercise, however, the conclusions drawn from the amenity-interaction approach match intuition better than those implied by Table 6, making them appear more credible. 4.6  Discussion The results in Tables 3 and 5 suggest that high- and low-education workers value climate mildness more than workers with educations in the middle range, and that young workers value climate mildness less than non-young workers. While the age-related valuation differ­ ences are expected, the evidence of strong valuation of climate mildness by low-education workers is unexpected and novel. Interestingly, the paper’s results can be used to predict how the wage distributions across groups within a city should differ between cities with low and high climate mildness. Focus­ ing first on the education groups, and recalling that the results show wages rising with education, the larger mildness wage effect for the inline-eq-IEq300 group relative to that for the inline-eq-IEq301 group implies that the wage gap between those two groups becomes larger when climate mildness increases (with inline-eq-IEq302 wage falling by more). Similarly, the larger mild­