Lecture 5: Urban Sorting, Skills, and Wages WWS 582a Esteban Rossi-Hansberg Princeton University ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 1 / 23 Introduction Wages are higher in larger cities Why? I I I Workers more productive there? Externalities? Positive assortative matching? Human capital accumulation? Urban costs can explain why not everyone goes to cities but not why …rm stay there I I All top cities have more establishments per capita than the US as a whole So we need a di¤erent mechanism Are the e¤ects dynamic or static? Large body of evidence shows basic fact for a wide variety of circumstances and periods Start by looking at evidence in Glaeser and Mare (2001) ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 2 / 23 The Wage-Size Premium in Cities Cities and Skills 317 Fig. 1.—Wages and SMSA population. Wage p 2,732 log (population) 1 4,332 (340); R2 p .579; number of observations p 49. Data from Statistical Abstract of the United States (Austin, TX: Reference, 1992), tables 42, 670. The unit of observation in both of these regressions is the SMSA. Standard errors are in parentheses beneath parameter estimates. ERH Kuznets 1970 for early data). In 1970, the urban wage premium was slightly larger than it is today; families in Standard Metropolitan Statistical (Princeton University ) Lecture Urban Sorting, Skills, and Wages 36% more than famAreas (SMSAs) with over 1 5:million residents earned 3 / 23 Glaeser and Mare (2001) Two basic questions: I I Is it that most skilled sort into cities or that cities improve productivity? Is the e¤ect important when people get to the city or do wages grow over time faster? ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 4 / 23 Sorting Most skilled might sort into cities because: I I Information ‡ows are relatively more valuable to them Consumer cities might be more attractive for skilled people If sorting is important: I I I Urban wage premium even after controlling for local prices Fixed-e¤ect estimates of the urban wage premium should be zero Factors that lead individuals to move into cities, but which are not correlated with individual ability, should not be correlated with higher wages ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 5 / 23 Timing of e¤ects Most standard theories imply that e¤ects happen at impact I So wages should jump up when people move to cities and should jump down when they move out Alternatively, cities might act through human capital accumulation or labor-market matching I In this case wages should grow over time and should not jump down when worker leave ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 6 / 23 Labor Supply In order to have a spatial equilibrium real wages per unit of skill equalize: φk ω i needs to be constant across cities i P i I φk = units of skill, ω i = wage in city i , Pi = price index in city i I Implies that W̃i W̃j = φ̃i φ̃j + log PPji where W̃i log of geometric mean of nominal wages So if W̃i W̃j log PPji = φ̃i φ̃j = 0, there are no ability di¤erences 320 Glaeser and Maré across cities I Fig. 2.—Wages adjusted by cost of living. Wage/cost of living p 213 log (population) 1 21828 (455); R2 p .006; number of observations p 37. Data from Statistical Abstract of the United States (Austin, TX: Reference, 1992), tables 42, 670; ACCRA Cost of Living Index, vol. 25, no. 3 (Louisville, KY: ACCRA, 1992). The unit of observation in both of these regressions is the SMSA. Standard errors are in parentheses beneath parameter estimates. ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 7 / 23 Labor Demand In order for …rms to demand workers in a city and pay higher wages it most be that they I I Obtain higher productivity Charge higher prices Suppose …rms maximize: Ai K σ L1 I I σ ωi L RK L is labor in unit of e¢ ciency and Ai includes e¢ ciency and prices 1/(1 Then, …rm maximization and zero pro…ts imply ω i = cR σ/(1 σ) Ai (where c is some constant) σ) Implies that W̃i W̃j = φ̃i φ̃j + 1 1 σ log Ai Aj So the goal is to obtain an estimate of Ai /Aj If workers in cities are better in an "unobserved" way this will be complicated ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 8 / 23 Using individual level data Estimate the regression log (Wkt ) = Xkt β + Lkt Γ + φk + εkt where Wkt is the hourly wage, Xkt is a vector of individual characteristics, Lkt is an indicator of an urban area, and φk denotes individual ability If φk omitted there is a potential bias, but could be solved with …xed e¤ects (lose some information) ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 9 / 23 Main results Table 3 Base Regressions 1990 Census Basic Wage Equation (1) 1990 Census Basic Wage Equation with PSID Occupational Basic Wage Education Equation (2) (3) Dense metropolitan premium .287 (.00) Nondense metropolitan premium .191* (.00) Experience dummies Yes Education dummies Yes Nonwhite 2.169* (.00) Average education in (one-digit) occupational group Tenure AFQT Time dummies No 20.4 Adjusted R2 (%) N 332,609 PSID Basic Wage Equation with Labor Market Variables (4) NLSY Basic Wage Equation (5) NLSY Basic Wage Equation with Occupational Education (6) NLSY Basic Wage Equation (7) NLSY Fixed-Effects Estimator (8) PSID Individual Fixed-Effects Estimator (9) .269* (.00) .282* (.01) .259* (.01) .249* (.01) .245* (.01) .243* (.01) .109* (.01) .045* (.01) .179* (.00) .148* (.01) .133* (.01) .153* (.01) .147* (.01) .141* (.01) .070* (.01) .026* (.01) Yes Yes Yes 2.156* (.00) Yes 2.193*(.01) .055* (.00) No 21.6 332,609 Yes Yes Yes Yes 2.173* (.01) 2.159* (.01) .039* (.00) .015* (.00) Yes 30.2 39,485 Yes 34.7 39,485 Yes 29.4 40,194 Yes Yes Yes Yes Yes 2.137* (.01) Yes 2.087* (.01) Yes N.A. Yes N.A. .034* (.00) .001* (.00) .027* (.00) .001* (.00) .002* (.00) Yes 33.7 40,194 .009* (.00) .000* (.00) N.A. Yes 28.4 40,194 Yes 33.0 40,194 .016* (.00) .010* (.00) Yes 20.6 39,485 Note.—Numbers in parentheses are standard errors. PSID p Panel Study of Income Dynamics; NLSY p National Longitudinal Study of Youth; AFQT p Armed Forces Qualification Test. * Significant at 1% level. ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 10 / 23 Interpretation Two interpretations of the result: I I The urban wage premium is all omitted ability factors Urban wage premium is not closely tied (temporally) to moving to a city Ideally, one would like to instrument for urban resident with variables that predict urban status and are orthogonal to unobserved ability I But hard to …nd: Urbanization in parent’s state of residence? ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 11 / 23 Growth of level e¤ect? Estimate exit exit Itenter log (Wkt ) = Xkt β + Lkt Γ + φk + ∑ γenter +j + ∑ γj It +j + εkt j j j exit where Itenter +j and It +j are dummies indicating when the agent entered or exited the urban area The parameters γenter and γexit indicate the urban premium j years before j j the move ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 12 / 23 Dynamic e¤ects Table 5 Analysis of Movers Nonmovers living in a metropolitan area Move to a metropolitan area: Observed 5 or more years before a move Observed 3–5 years before a move Observed 1–3 years before a move Observed within 1 year before a move Observed within 1 year after moving Observed 1–3 years after moving Observed 3–5 years after moving Observed 5 or more years after moving Leave a metropolitan area: Observed 5 or more years before a move Observed 3–5 years before a move Observed 1–3 years before a move Observed within 1 year before a move Observed Cities and within Skills 1 year after moving Table 5 (Continued) Observed 1–3 years after moving Observed 3–5 years after moving Observed 5 or more years after moving Regressions contain education, experience, nonwhite and time dummies and occupational education Adjusted R2 (%) N NLSY OLS (1) NLSY Individual (Spell) Fixed Effects (2) .168* (.01) N.A. .069* (.02) 2.021 (.02) 2.040** (.02) 2.022 (.02) PSID OLS (3) .203* (.01) PSID Individual Fixed Effects (4) N.A. .093* (.02) 2.138* (.01) 2.067* (.02) .028 (.02) 2.141* (.02) 2.056* (.02) 2.010 (.02) 2.151* (.02) 2.048* (.02) N.A. 2.092* (.02) N.A. .079* (.02) .073* (.02) 2.113* (.02) 2.036** (.02) .111* (.01) .114* (.02) 2.082* (.02) 2.008 (.02) .125* (.01) .123* (.02) 2.053* (.02) .030*** (.02) .118* (.01) .105* (.02) 2.050* (.01) .019 (.02) .049** (.02) .021 (.02) .188* (.01) .018 (.01) .039*** (.02) 2.001 (.02) .148* (.01) 2.006 (.01) .053* (.02) 2.002 (.02) .165* (.01) .010 (.01) .062* (.02) N.A. .150* (.02) N.A. .050** (.02) 2.036*** (.02) .128* (.02) 2.024*** (.01) .005 (.02) .116* (.01) .028 (.02) NLSY OLS (1) .006 (.02) 2.068* (.02) NLSY Individual 2.023 (.02) (Spell) Fixed Effects (2) 2.027 (.02) .097* (.02) PSID OLS (3) .148* (.01) 2.041* (.01) PSID 2.035** (.02) Individual Fixed Effects (4) 2.008 (.01) Yes 26.6 40,822 Yes 25.9 40,822 Yes 34.4 39,485 Yes 19.3 39,485 337 Note.—Numbers in parentheses are standard errors. NLSY p National Longitudinal Study of Youth; OLS p ordinary least squares; PSID p Panel Study of Income Dynamics. * Significant at 1% level. ** Significant at 5% level. *** Significant at 10% level. ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages enter exit 13 / 23 32,000 de la Roca and Puga (2014) for Spain Madrid 28,000 Girona Manresa Palma de Mallorca Tarragona − Reus Burgos Castellón de la Plana Zaragoza Valencia Toledo Puertollano A Coruña Granada Logroño Huesca Guadalajara Valladolid Sevilla Lleida Santander − Torrelavega Ferrol CiudadSagunt Real Vigo − Pontevedra Asturias Huelva León Almería Ávila Málaga Jaén Alacant − Elx Murcia Las Palmas de Gran Canaria Ourense Cartagena Santiago de Compostela Costa del Sol Albacete Santa CruzCórdoba de Tenerife − La Laguna Cuenca Badajoz Motril Segovia Cádiz Algeciras 24,000 20,000 Mean annual earnings (€, full−time equivalent, log scale ) Barcelona Aranjuez Palencia Roquetas de Mar Gandía Orihuela El Ejido Zamora Linares Cáceres Alcoi Costa Blanca PonferradaLugo Mérida Lorca de la Reina Talavera Torrevieja Arrecife Vélez−Málaga Sanlúcar de Barrameda 16,000 Utrera Salamanca Tenerife Sur Gran Canaria Elda −Sur Petrer 50,000 125,000 250,000 City size 500,000 1,000,000 2,000,000 (people within 10km of average worker, log scale) Figure 1: Mean earnings and city size experience. Since these dynamic advantages are transformed in higher human capital, they may remain beneficial even when a worker relocates. ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 14 / 23 30% Elasticity: 0.046 20% Barcelona Burgos − Reus ManresaTarragona Girona Palma de Mallorca Castellón de la Plana Granada Madrid Zaragoza 0% 10% Costa del Sol −10% Earnings premium, static estimation, pooled ols 40% Controlling for Worker Characteristics (Static) Puertollano Guadalajara Sagunt Málaga Motril Toledo Asturias Logroño Huelva Santander − Torrelavega Sevilla Costa Blanca Algeciras A Coruña Valladolid Córdoba Cádiz Alacant de MarLleida Sanlúcar Roquetas de Barrameda − Elx Ferrol Ciudad Real Gandía Albacete CartagenaVigo − Pontevedra Jaén Murcia Almería León Aranjuez Las Palmas de Gran Canaria Vélez−Málaga El EjidoSantiago de Compostela Utrera Palencia Ponferrada Linares Cuenca Santa Cruz de Tenerife − La Laguna Ávila LorcaArrecife Orihuela Badajoz Segovia Torrevieja Talavera deSur la Reina Salamanca Tenerife Alcoi Mérida Zamora Elda − Petrer Cáceres Ourense Gran Canaria Lugo Sur Huesca 50,000 125,000 250,000 City size 500,000 Valencia 1,000,000 2,000,000 (people within 10km of average worker, log scale) Figure 2: Static ols estimation of the city-size premium equation (2) includes the omitted variables: ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 15 / 23 35% 30% 15% 20% 25% Madrid always 10% Madrid 5 years, then Santiago Sevilla always 5% 0% Earnings premium relative to Santiago — median size 40% Homogenous Dynamic E¤ects Sevilla 5 years, then Santiago 0 1 2 3 4 5 6 7 8 9 10 Years worked 40% Panel (a) Profiles allowing for learning benefits of bigger cities ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 16 / 23 40% Homogenous Dynamic E¤ects Elasticity: 0.047 30% 20% Madrid Zaragoza 10% Castellón de la Plana 0% Medium−term earnings premium, dynamic estimation, fixed−effects Barcelona Palma de Mallorca Tarragona − Reus Girona Burgos Toledo Lleida Puertollano Guadalajara Huesca Sevilla Torrevieja Costa del SolManresaAlbacete Huelva Granada Asturias Costa Blanca ZamoraSagunt Las Palmas de Gran Canaria Jaén Logroño Alacant − Elx Ciudad Real Valladolid Motril Málaga Córdoba Aranjuez Almería Palencia SantanderSanta − Torrelavega Cádiz Murcia− La Laguna Cruz de Tenerife Roquetas de Mar Segovia Gran Canaria Sur León ÁvilaVélez−Málaga Tenerife Sur Vigo − Pontevedra Orihuela − Petrer Salamanca Talavera de la Elda Reina Santiago de Compostela El Ejido Cartagena Arrecife Utrera Badajoz A Coruña Alcoi Algeciras Cuenca Mérida de Lugo Sanlúcar Barrameda Ferrol LinaresCáceres Gandía Lorca Ourense −10% Ponferrada Valencia 50,000 125,000 250,000 City size 500,000 1,000,000 2,000,000 (people within 10km of average worker, log scale) Figure 4: Dynamic fixed-effects estimation of the medium-term city-size premium same city evaluated at the average experience in a single location for workers in our sample (7.24 ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 17 / 23 25% 30% 35% Madrid always, th worker fixed-effect at 75 percentile 15% 20% Madrid always, th worker fixed-effect at 25 percentile 10% Sevilla always, th worker fixed-effect at 75 percentile 5% 0% Earnings premium relative to Santiago — median size 40% Heterogenous Dynamic E¤ects Sevilla always, th worker fixed-effect at 25 percentile 0 1 2 3 4 5 6 7 8 9 10 Years worked Figure 5: Earnings profile relative to median-sized city, high- and low-ability worker 6. Sorting ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 18 / 23 1.25 0 Worker fixed−effects 1 1.25 0 Worker fixed−effects 0.50 0.75 5 biggest cities 0.25 Smaller cities −1 Densities 1.00 1.00 0.75 Densities 0.25 0.50 5 biggest cities 0.00 5 biggest cities −1 Panel (b) Fixed-effects, homogeneous dynamic and static premium 1.25 Panel (a) Fixed-effects, heterogeneous dynamic and static premium 0.75 1.00 Worker fixed−effects 1 Smaller cities 0.25 Densities 0 0.00 −1 1 Panel (c) Fixed-effects, static premium 0.00 0.00 5 biggest cities 0.50 0.75 0.50 Smaller cities 0.25 Densities 1.00 1.25 Distribution of Workers Smaller cities −1 0 Earnings 1 Panel (d) Earnings Figure 6: Comparisons of worker fixed-effects distributions across cities ERH appears (Princeton University Lecture 5: Urban Skills,that and big-city Wages experience has for them larger than) it is (this estimation mixes the Sorting, extra value 19 / 23 sample the weekly job history data four times every year for those who become attached to the labour force after 1 January, 1978 and observe wages in about one-quarter of the observations. Appendix A details how we construct the data including our sample selection rules. Baum-Snow and Pavan (2011) 2.3. Descriptive patterns fixed effects additionally reduces these coefficients to 0∙07 and 0∙15. TABLE 1 Estimates of city size wage premia No controls 1980’s MSA population Individual controls Individual controls and fixed effects Temporally deflated only 2 1 No controls 3 Individual controls Individual control and fixed effects Spatially and temporally deflated 3 1 2 Panel A: full sample 0∙25–1∙5 million > 1∙5 million R-squared 0∙19∗∗∗ (0∙03) 0∙29∗∗∗ (0∙03) 0∙04 0∙14∗∗∗ (0∙03) 0∙22∗∗∗ (0∙03) 0∙26 0∙21∗∗∗ (0∙05) 0∙27∗∗∗ (0∙05) 0∙03 0∙20∗∗∗ (0∙04) 0∙27∗∗∗ (0∙05) 0∙18 0∙12∗∗∗ (0∙03) 0∙22∗∗∗ (0∙03) 0∙03 0∙12∗∗∗ (0∙03) 0∙22∗∗∗ (0∙03) 0∙14 0∙07∗∗∗ (0∙02) 0∙15∗∗∗ (0∙02) 0∙60 0∙14∗∗∗ (0∙03) 0∙11∗∗∗ (0∙03) 0∙01 0∙09∗∗∗ (0∙02) 0∙05∗ (0∙03) 0∙24 0∙05∗∗∗ (0∙02) 0∙03 (0∙02) 0∙59 0∙15∗∗∗ (0∙04) 0∙09∗ (0∙05) 0∙01 0∙14∗∗∗ (0∙04) 0∙09∗ (0∙05) 0∙18 0∙05∗ (0∙03) 0∙01 (0∙040) 0∙61 0∙09∗∗∗ (0∙03) 0∙04 (0∙03) 0∙14 0∙05∗ (0∙03) 0∙05 (0∙04) 0∙52 Panel B: College or more 0∙25–1∙5 million > 1∙5 Million R-squared 0∙07∗∗ (0∙03) 0∙12∗∗∗ (0∙04) 0∙60 Downloaded from http://restud.oxfordjournals.org/ by guest on March 7, 2012 reports city size wage premia with and without adjustment for cost of living differences Study similar Table set1locations. of issues butnominal with recent and across The estimated wagemore premium for medium-sized citiesbetter over smaller data areas is 0∙19, while that for large cities is 0∙29. Controlling for education and a cubic in work U-shaped pattern in real wages experience reduces these coefficients to 0∙14 and 0∙22, respectively. Controlling for individual Panel C: high school graduates only 0∙25–1∙5 million > 1∙5 million R-squared 0∙06∗ (0∙03) 0∙18∗∗∗ (0∙04) 0∙52 0∙09∗∗∗ (0∙03) 0∙03 (0∙04) 0∙01 Notes: Each regression in Panel A uses data on 1754 white men and has 25,363 observations based on quarterly data. Panel B has 7,555 observations on 583 individuals. Panel C has 10,436 observations on 674 individuals. Individual controls are four educational dummies and cubic polynomials in work experience. We only include observations from the first 15 years of work experience. Standard errors are clustered by location. Complete sample selection rules are explained in Appendix A. *** indicates significance at the 1% level, ** indicates significance at the 5% level, and * indicates significance at the 10% level. ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 20 / 23 City Size, Job Turnover, and Unemployment UNDERSTANDING THE CITY SIZE WAGE GAP BAUM-SNOW & PAVAN 7 TABLE 2 Attributes at 15 years of work experience as functions of location Location Size Job–job changes Within To 1 2 Job-unemployment-job changes Within Length To Length 3 4 Fraction in location At Entry At 15 Yrs 5 6 7 8 0∙4 0∙3 0∙3 4∙7 3∙4 2∙2 0∙32 0∙36 0∙32 0∙30 0∙39 0∙30 2∙3 3∙4 2∙1 0∙23 0∙40 0∙37 0∙21 0∙42 0∙37 4∙6 3∙0 2∙4 0∙36 0∙36 0∙28 0∙37 0∙37 0∙25 Panel A: full sample Small Medium Large 2∙7 3∙0 3∙0 0∙7 0∙6 0∙4 1∙8 1∙7 1∙6 Small Medium Large 1∙7 2∙2 2∙4 0∙9 0∙7 0∙6 0∙7 0∙8 0∙7 Small Medium Large 3∙1 3∙3 3∙0 0∙6 0∙4 0∙3 22∙9 19∙1 16∙0 Panel B: college or more 0∙4 0∙3 0∙3 Panel C: high school graduates only 2∙1 2∙2 2∙3 31∙2 27∙1 26∙7 0∙4 0∙3 0∙2 Notes: The sample includes all individuals used for the regressions in Table 1 except those who we do not observe for at least 15 years of work experience. Columns marked “Within” report numbers of job changes within location, whereas columns marked “To” report job changes across locations to locations of the indicated size. Each entry is calculated as the total amount of the quantity indicated in the column header for the sample indicated in the panel header divided by the sum of the fraction of time spent by everybody in the sample in the location category given in the row header. Therefore, each entry is the amount of each quantity experienced by the average individual over the first 15 years of work experience if he were to live in the indicated location for the full time. “Length” refers to total length of all unemployment spells. “LF” stands for labour force. Bootstrapped standard errors with samples clustered by individual reveal that the only statistically significant medium–small and large–small differences in Columns 1–6 are in Panel/Columns A2, A5, B1, and C2. College graduates are significantly more likely to be located in large locations at LF entry and 15 years of experience. The full sample includes 1425 men, including 466 in the college sample and 566 in the high school sample. or rural counties of the indicated size, while those headed by “To” indicate transitions that also 5: counties Urban Sorting, and Wages to MSAsLecture or rural of theSkills, indicated size. Such “To” migration may ERH (Princeton involve Universitymigration ) Downloaded from http://restud.oxfordjournals.org/ by guest on March 7, 2 6∙0 6∙2 7∙2 21 / 23 Firm-Worker match quality not a driver REVIEW OF ECONOMIC STUDIES 8 TABLE 3 1Log wage regressions Temporally deflated only All 1Experience in small 1Experience in medium 1Experience in large 1Experience 2 1Exp3 Job-un-job in small Job-un-job in medium Job-un-job in large Job-job+move to small Job-job+move to medium Job-job+move to large Spatially and temporally deflated HS All College HS 0∙046∗∗ (0∙012) 0∙056∗∗∗ (0∙010) 0∙059∗∗∗ (0∙011) 0∙001 (0∙001) −0∙000∗ (0∙000) (0∙019) 0∙062∗∗∗ (0∙018) 0∙064∗∗∗ (0∙023) 0∙000 (0∙002) −0∙000 (0∙000) 0∙016 (0∙023) 0∙046∗∗∗ (0∙013) 0∙055∗∗∗ (0∙012) 0∙003 (0∙002) −0∙000∗ (0∙000) 0∙031∗∗ (0∙012) 0∙054∗∗∗ (0∙010) 0∙057∗∗∗ (0∙010) 0∙002 (0∙001) −0∙000∗∗ (0∙000) 0∙046∗∗ (0∙019) 0∙060∗∗∗ (0∙018) 0∙062∗∗∗ (0∙022) 0∙001 (0∙002) −0∙000 (0∙000) 0∙017 (0∙023) 0∙045∗∗∗ (0∙013) 0∙054∗∗∗ (0∙012) 0∙004 (0∙002) −0∙000 ∗ ∗ (0∙000) 0∙066∗∗∗ (0∙018) 0∙097∗∗∗ (0∙010) 0∙079∗∗∗ (0∙012) 0∙081∗ (0∙043) 0∙126∗∗∗ (0∙024) 0∙083∗∗∗ (0∙022) 0∙078∗∗∗ (0∙028) 0∙094∗∗∗ (0∙016) 0∙078∗∗∗ (0∙015) 0∙066∗∗∗ (0∙018) 0∙096∗∗∗ (0∙010) 0∙078∗∗∗ (0∙012) 0∙082∗ (0∙043) 0∙126∗∗∗ (0∙024) 0∙085∗∗∗ (0∙023) 0∙079∗∗∗ (0∙028) 0∙093∗∗∗ (0∙016) 0∙077∗∗∗ (0∙015) −0∙017 (0∙017) −0∙027 (0∙019) 0∙021 (0∙015) 0∙099∗∗∗ (0∙032) 0∙116∗∗∗ (0∙036) 0∙085∗∗ (0∙034) 0∙043 (0∙092) −0∙022 (0∙047) 0∙026 (0∙054) 0∙212∗∗∗ (0∙055) 0∙118∗∗∗ (0∙044) 0∙113∗∗∗ (0∙041) −0∙050∗∗ (0∙025) −0∙028 (0∙026) 0∙025 (0∙020) 0∙032 (0∙057) 0∙019 (0∙058) −0∙134 (0∙101) −0∙015 (0∙017) −0∙028 (0∙019) 0∙021 (0∙015) 0∙126∗∗∗ (0∙032) 0∙133∗∗∗ (0∙032) 0∙055∗ (0∙032) 0∙043 (0∙092) −0∙022 (0∙046) 0∙028 (0∙054) −0∙047∗ (0∙025) −0∙029 (0∙026) 0∙023 (0∙019) 0∙245∗∗∗ (0∙057) 0∙144∗∗∗ (0∙043) 0∙107∗∗∗ (0∙040) 0∙053 (0∙058) 0∙027 (0∙058) −0∙204∗∗ (0∙100) Job-un-job + move to small Job-un-job + move to medium Job-un-job + move to large −0∙033 (0∙042) −0∙072∗ (0∙044) 0∙161∗∗∗ (0∙055) −0∙013 (0∙101) −0∙007 (0∙095) 0∙184∗∗ (0∙074) 0∙000 (0∙058) −0∙089 (0∙063) 0∙234∗∗∗ (0∙071) 0∙004 (0∙041) −0∙028 (0∙044) 0∙109∗ (0∙058) 0∙019 (0∙100) 0∙028 (0∙091) 0∙143∗∗ (0∙060) 0∙029 (0∙057) −0∙025 (0∙062) 0∙158∗ (0∙087) Unobservable job to small Unobservable job to medium Unobservable job to large −0∙105∗∗∗ (0∙038) −0∙086 (0∙074) −0∙077 (0∙080) −0∙180∗∗ (0∙082) −0∙035 (0∙197) −0∙014 (0∙186) −0∙140∗∗ (0∙068) −0∙164∗ (0∙087) −0∙107 (0∙099) −0∙100∗∗ (0∙040) −0∙085 (0∙073) −0∙085 (0∙081) −0∙163∗∗ (0∙081) −0∙052 (0∙191) −0∙038 (0∙186) −0∙142∗∗ (0∙069) −0∙152∗ (0∙086) −0∙093 (0∙100) 6,276 0∙028 9,020 0∙020 21,481 0∙020 6,276 0∙030 Observations R-squared 21,481 0∙019 Downloaded from http://restud.oxfordjournals.org/ by guest on March 7, 2012 Job to job in small Job to job in medium Job to job in large College 0∙031∗∗ 9,020 0∙020 Notes: Each column is a separate regression of the change in log wage on functions of experience or labour market transitions listed at left. The regression specification is given by equation (6) in the text with standard errors clustered by location. The 185 cases of gaps between wage observations exceeding ten quarters are excluded. *** indicates significance at the 1% level, ** indicates significance at the 5% level, and * indicates significance at the 10% level. ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 22 / 23 Conclusions Returns to experience and wage-level e¤ects are the most important mechanisms contributing to the overall city size wage premium Di¤erences in wage intercepts across location categories are more important for generating medium–small wage gaps Di¤erences in returns to experience are more important for generating large–small city size wage gaps Sorting on unobserved ability within education group and di¤erences in labour market search frictions independently contribute slightly negatively, if at all, to observed city size wage premia ERH (Princeton University ) Lecture 5: Urban Sorting, Skills, and Wages 23 / 23