Summary statistics for nhamcsopd2006 dataset : by Jean Roth , jroth@nber.org , 28 Mar 2016 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- vmonth | 35,105 6.296596 3.423012 1 12 vyear | 35,105 2006 0 2006 2006 vdayr | 35,105 3.951574 1.466522 1 7 age | 35,105 36.34061 23.79367 0 100 sex | 35,105 1.388862 .4874988 1 2 -------------+--------------------------------------------------------- pregnant | 35,105 4.563623 3.041822 1 9 gestwk | 35,105 85.79311 15.14388 1 99 ethnic | 35,105 1.817035 .3866437 1 2 race | 35,105 1.437231 .8925579 1 6 usetobac | 35,105 1.775474 .9685736 0 3 -------------+--------------------------------------------------------- notobac | 35,105 5.176556 3.503863 1 9 paypriv | 35,105 .3782367 .484954 0 1 paymcare | 35,105 .1574135 .3641953 0 1 paymcaid | 35,105 .3629113 .4808464 0 1 paywkcmp | 35,105 .0073779 .0855783 0 1 -------------+--------------------------------------------------------- payself | 35,105 .0796468 .2707494 0 1 paynochg | 35,105 .0329298 .1784554 0 1 payoth | 35,105 .0475146 .2127399 0 1 paydk | 35,105 .0329013 .1783808 0 1 paytype | 35,105 2.723572 1.851571 0 8 -------------+--------------------------------------------------------- injdet | 35,105 3.950036 .97625 1 9 injury | 35,105 .1033186 .3043789 0 1 rfv1 | 35,105 30257.88 17062.5 10050 90000 rfv2 | 35,105 67248.63 32314.66 10050 90000 rfv3 | 35,105 81753.81 22790.09 10050 90000 -------------+--------------------------------------------------------- rfv13d | 35,105 3025.757 1706.271 1005 9000 rfv23d | 35,105 6724.849 3231.488 1005 9000 rfv33d | 35,105 8175.375 2279.027 1005 9000 primcare | 35,105 1.732659 .5694679 0 3 refer | 35,105 3.291155 2.911962 0 8 -------------+--------------------------------------------------------- senbefor | 35,105 1.192594 .3943422 1 2 pastvis | 35,105 3.855006 2.191584 1 8 major | 35,105 2.425837 1.521357 0 5 diag1 | 0 diag2 | 0 -------------+--------------------------------------------------------- diag3 | 0 diag13d | 0 diag23d | 0 diag33d | 0 prdiag1 | 35,105 .0732944 .7228923 0 8 -------------+--------------------------------------------------------- prdiag2 | 35,105 4.11007 3.989656 0 8 prdiag3 | 35,105 6.17704 3.350094 0 8 arthrtis | 35,105 .0850591 .2789736 0 1 asthma | 35,105 .0665147 .2491833 0 1 cancer | 35,105 .0588805 .2354043 0 1 -------------+--------------------------------------------------------- castage | 35,105 7.693092 1.277048 0 8 cebvd | 35,105 .0142145 .1183759 0 1 chf | 35,105 .0163225 .1267142 0 1 crf | 35,105 .0097707 .0983641 0 1 copd | 35,105 .0261216 .1594993 0 1 -------------+--------------------------------------------------------- deprn | 35,105 .1094146 .3121631 0 1 diabetes | 35,105 .1168779 .3212794 0 1 hyplipid | 35,105 .0743769 .262387 0 1 htn | 35,105 .1873237 .3901767 0 1 ihd | 35,105 .0219627 .1465638 0 1 -------------+--------------------------------------------------------- obesity | 35,105 .0732659 .2605762 0 1 ostprsis | 35,105 .0115083 .1066593 0 1 nochron | 35,105 .5701752 .5751267 0 2 totchron | 35,105 5.107221 19.9009 0 99 dmp | 35,105 5.73152 2.612294 1 9 -------------+--------------------------------------------------------- htin | 35,105 81.68042 21.21457 13 99 wtlb | 35,105 425.1294 403.4701 3 999 bmi | 35,105 650.5196 466.1983 8.89 999 tempf | 35,105 449.9443 488.2665 0 1096 bpsys | 35,105 469.7731 428.5773 12 999 -------------+--------------------------------------------------------- bpdias | 35,105 440.7056 453.474 0 999 diagscrn | 35,105 .9073921 .3682325 0 2 breast | 35,105 .0545791 .2271601 0 1 pelvic | 35,105 .0758012 .2646835 0 1 rectal | 35,105 .0191995 .1372278 0 1 -------------+--------------------------------------------------------- skin | 35,105 .1091013 .3117707 0 1 depress | 35,105 .0153255 .1228455 0 1 anyimage | 35,105 .1753311 .3802555 0 1 bonedens | 35,105 .0042159 .0647941 0 1 mammo | 35,105 .0199117 .1396989 0 1 -------------+--------------------------------------------------------- mri | 35,105 .0399658 .1958817 0 1 ultrasnd | 35,105 .0480843 .2139475 0 1 xray | 35,105 .0751745 .2636764 0 1 othimage | 35,105 .0133314 .1146912 0 1 cbc | 35,105 .1301239 .3364445 0 1 -------------+--------------------------------------------------------- electrol | 35,105 .0467455 .2110962 0 1 glucose | 35,105 .0632958 .2434977 0 1 hgba | 35,105 .0337274 .1805292 0 1 cholest | 35,105 .046717 .211035 0 1 psa | 35,105 .0073209 .0852497 0 1 -------------+--------------------------------------------------------- otherbld | 35,105 .1263923 .3322956 0 1 scopproc | 35,105 .0237858 .1523833 0 1 sigcolon | 35,105 .0101695 .1003312 0 1 scopewi1 | 0 scopewi2 | 0 -------------+--------------------------------------------------------- scpwi13d | 0 scpwi23d | 0 scpwi12d | 0 scpwi22d | 0 biopsy | 35,105 .013132 .1138418 0 1 -------------+--------------------------------------------------------- chlamyd | 35,105 .0144994 .1195388 0 1 papconv | 35,105 .0122205 .1098703 0 1 papliq | 35,105 .0168922 .1288693 0 1 papunsp | 35,105 .0084888 .0917442 0 1 hpvdna | 35,105 .0069506 .0830811 0 1 -------------+--------------------------------------------------------- ekg | 35,105 .0378294 .1907861 0 1 spiro | 35,105 .0089731 .0943017 0 1 urine | 35,105 .09144 .2882379 0 1 httake | 35,105 .4424726 .4966866 0 1 wttake | 35,105 .6743769 .4686139 0 1 -------------+--------------------------------------------------------- temptake | 35,105 .4592793 .4983462 0 1 blodpres | 35,105 .6042729 .4890133 0 1 othdiag | 35,105 .1580402 .3647839 0 1 diagsc1 | 0 diagsc2 | 0 -------------+--------------------------------------------------------- digsc13d | 0 digsc23d | 0 digsc12d | 0 digsc22d | 0 totdiag | 35,105 6.23706 15.32181 0 99 -------------+--------------------------------------------------------- healthed | 35,105 .5431135 .536631 0 2 asthmaed | 35,105 .0141006 .1179073 0 1 dietnutr | 35,105 .1460761 .3531875 0 1 exercise | 35,105 .0663723 .2489353 0 1 grwthdev | 35,105 .0489959 .2158625 0 1 -------------+--------------------------------------------------------- injprev | 35,105 .0337274 .1805292 0 1 stresmgt | 35,105 .0362626 .1869456 0 1 tobaced | 35,105 .0347244 .1830835 0 1 wtreduc | 35,105 .0355505 .1851692 0 1 othlthed | 35,105 .3552485 .4785954 0 1 -------------+--------------------------------------------------------- tothlted | 35,105 2.742316 13.75727 0 99 nonmed | 35,105 .3202963 .5254081 0 2 cam | 35,105 .0042159 .0647941 0 1 dme | 35,105 .0085743 .0922009 0 1 homehlth | 35,105 .0058681 .0763796 0 1 -------------+--------------------------------------------------------- hospice | 35,105 .0004843 .0220009 0 1 pt | 35,105 .0216493 .1455378 0 1 radther | 35,105 .0016522 .0406141 0 1 spocther | 35,105 .0073494 .0854141 0 1 psychoth | 35,105 .0583962 .2344945 0 1 -------------+--------------------------------------------------------- othmntl | 35,105 .0402222 .1964827 0 1 excision | 35,105 .0156673 .1241864 0 1 ortho | 35,105 .0298248 .1701062 0 1 wound | 35,105 .0456345 .2086942 0 1 othproc | 35,105 .0976784 .2968835 0 1 -------------+--------------------------------------------------------- othproc1 | 0 othproc2 | 0 othproc3 | 0 othproc4 | 0 othpr13d | 0 -------------+--------------------------------------------------------- othpr23d | 0 othpr33d | 0 othpr43d | 0 othpr12d | 0 othpr22d | 0 -------------+--------------------------------------------------------- othpr32d | 0 othpr42d | 0 totnonmed | 35,105 3.214898 16.61437 0 99 med | 35,105 .7334283 .5045774 0 2 med1 | 35,105 58884.41 38434.75 2 99999 -------------+--------------------------------------------------------- med2 | 35,105 71098.46 33794.75 2 99999 med3 | 35,105 77820.48 28722.98 3 99999 med4 | 35,105 81901.4 24220.56 3 99999 med5 | 35,105 84328.43 20644.42 3 99999 med6 | 35,105 85769.89 17941.58 3 99999 -------------+--------------------------------------------------------- med7 | 35,105 86835.26 15668.28 2 99999 med8 | 35,105 87854.62 12912.6 3 99999 ncmed1 | 35,105 3.854266 3.120676 1 9 ncmed2 | 35,105 5.346048 3.167409 1 9 ncmed3 | 35,105 6.255519 2.838099 1 9 -------------+--------------------------------------------------------- ncmed4 | 35,105 6.830338 2.44908 1 9 ncmed5 | 35,105 7.169719 2.124519 1 9 ncmed6 | 35,105 7.400883 1.838105 1 9 ncmed7 | 35,105 7.561316 1.592809 1 9 ncmed8 | 35,105 7.693092 1.346813 1 9 -------------+--------------------------------------------------------- numnew | 35,105 .5915397 1.116786 0 8 numcont | 35,105 1.304885 2.094928 0 8 nummed | 35,105 1.977695 2.26188 0 8 noprovid | 35,105 .0144424 .1193072 0 1 phys | 35,105 .7994303 .4004324 0 1 -------------+--------------------------------------------------------- physasst | 35,105 .055747 .2294359 0 1 npnmw | 35,105 .0909842 .2875907 0 1 rnlpn | 35,105 .4922091 .4999464 0 1 othprov | 35,105 .2927503 .4550313 0 1 nodisp | 35,105 .0201396 .1404797 0 1 -------------+--------------------------------------------------------- nofu | 35,105 .0570289 .2319012 0 1 retprn | 35,105 .2044153 .4032795 0 1 refothmd | 35,105 .1309785 .3373816 0 1 retappt | 35,105 .6989033 .4587412 0 1 telephon | 35,105 .0279163 .1647353 0 1 -------------+--------------------------------------------------------- refered | 35,105 .0038456 .0618945 0 1 admithos | 35,105 .0053838 .073178 0 1 othdisp | 35,105 .0233585 .1510415 0 1 patwt | 35,105 2911.499 4086.873 13 23801 region | 35,105 2.292551 1.060761 1 4 -------------+--------------------------------------------------------- msa | 35,105 1.104657 .3061159 1 2 owner | 35,105 1.265546 .4818545 1 3 blank | 0 hospcode | 35,105 119.3683 66.45015 1 242 clintype | 35,105 2.685743 1.761302 1 6 -------------+--------------------------------------------------------- patcode | 35,105 100.8965 85.14066 1 698 bdatefl | 35,105 .0101125 .1000527 0 1 sexfl | 35,105 .0093719 .0963552 0 1 ethnicfl | 35,105 .1647059 .3709202 0 1 racefl | 35,105 .1326022 .3391491 0 1 -------------+--------------------------------------------------------- senbefl | 35,105 .0215069 .1450688 0 1 pastfl | 35,105 .0854009 .2794814 0 1 drugid1 | 0 prescr1 | 23,679 1.286372 .6015126 1 3 contsub1 | 23,679 5.752017 .9443919 2 7 -------------+--------------------------------------------------------- comstat1 | 23,679 1.171671 .3771023 1 2 rx1cat1 | 23,679 149.6801 89.96235 1 899 rx1cat2 | 2,206 171.0467 94.65442 12 899 rx1cat3 | 352 194.6847 23.13333 180 270 rx1cat4 | 87 205 0 205 205 -------------+--------------------------------------------------------- rx1v1c1 | 23,679 106.8501 93.98448 1 899 rx1v1c2 | 2,206 85.21034 58.385 1 899 rx1v1c3 | 352 89.05114 19.24983 57 122 rx1v1c4 | 87 57 0 57 57 rx1v2c1 | 23,666 134.3279 202.1505 2 999 -------------+--------------------------------------------------------- rx1v2c2 | 2,205 112.2508 84.85135 4 340 rx1v2c3 | 352 106.3608 50.19731 65 270 rx1v2c4 | 87 66 0 66 66 rx1v3c1 | 14,712 187.0591 94.04807 59 999 rx1v3c2 | 0 -------------+--------------------------------------------------------- rx1v3c3 | 0 rx1v3c4 | 0 drugid2 | 0 prescr2 | 15,397 1.279275 .6036993 1 3 contsub2 | 15,397 5.748782 .9219435 2 7 -------------+--------------------------------------------------------- comstat2 | 15,397 1.127622 .3336796 1 2 rx2cat1 | 15,397 150.3276 89.22511 2 899 rx2cat2 | 1,647 186.3692 79.52813 12 340 rx2cat3 | 187 204.8984 27.73948 180 270 rx2cat4 | 116 205 0 205 205 -------------+--------------------------------------------------------- rx2v1c1 | 15,397 114.0888 95.60238 1 899 rx2v1c2 | 1,647 89.87675 57.58502 1 358 rx2v1c3 | 187 74.64171 23.46205 57 122 rx2v1c4 | 116 57 0 57 57 rx2v2c1 | 15,387 112.9251 132.736 2 999 -------------+--------------------------------------------------------- rx2v2c2 | 1,647 114.8992 82.36955 5 340 rx2v2c3 | 187 102.6684 68.46934 64 270 rx2v2c4 | 116 66 0 66 66 rx2v3c1 | 9,557 183.1736 93.18416 59 999 rx2v3c2 | 0 -------------+--------------------------------------------------------- rx2v3c3 | 0 rx2v3c4 | 0 drugid3 | 0 prescr3 | 10,290 1.260641 .5848178 1 3 contsub3 | 10,290 5.787269 .8426232 2 7 -------------+--------------------------------------------------------- comstat3 | 10,290 1.109329 .3120673 1 2 rx3cat1 | 10,290 150.4327 88.39776 2 899 rx3cat2 | 1,170 194.3726 77.38261 12 899 rx3cat3 | 105 212.0286 32.65597 180 270 rx3cat4 | 62 205 0 205 205 -------------+--------------------------------------------------------- rx3v1c1 | 10,290 117.3332 98.01419 1 899 rx3v1c2 | 1,170 90.1265 59.81169 1 899 rx3v1c3 | 105 76.57143 24.60373 57 122 rx3v1c4 | 62 57 0 57 57 rx3v2c1 | 10,288 106.9298 113.0146 2 999 -------------+--------------------------------------------------------- rx3v2c2 | 1,169 115.3516 81.24758 5 340 rx3v2c3 | 105 116.7429 81.3648 64 270 rx3v2c4 | 62 66 0 66 66 rx3v3c1 | 6,307 184.0547 97.49154 59 999 rx3v3c2 | 0 -------------+--------------------------------------------------------- rx3v3c3 | 0 rx3v3c4 | 0 drugid4 | 0 prescr4 | 6,958 1.263581 .5886414 1 3 contsub4 | 6,958 5.809141 .7973056 2 7 -------------+--------------------------------------------------------- comstat4 | 6,958 1.093561 .2912384 1 2 rx4cat1 | 6,958 150.9958 88.8462 2 899 rx4cat2 | 784 193.0587 74.93934 12 340 rx4cat3 | 56 217.7857 36.26604 180 270 rx4cat4 | 28 205 0 205 205 -------------+--------------------------------------------------------- rx4v1c1 | 6,958 120.4889 102.8069 1 899 rx4v1c2 | 784 87.4273 54.696 1 358 rx4v1c3 | 56 81.35714 25.13558 57 122 rx4v1c4 | 28 57 0 57 57 rx4v2c1 | 6,954 107.1544 113.765 2 999 -------------+--------------------------------------------------------- rx4v2c2 | 784 112.5702 80.54987 5 340 rx4v2c3 | 56 133.4286 89.13378 65 270 rx4v2c4 | 28 66 0 66 66 rx4v3c1 | 4,203 182.5686 90.30221 59 999 rx4v3c2 | 0 -------------+--------------------------------------------------------- rx4v3c3 | 0 rx4v3c4 | 0 drugid5 | 0 prescr5 | 4,997 1.256354 .5761838 1 3 contsub5 | 4,997 5.806484 .7808084 2 7 -------------+--------------------------------------------------------- comstat5 | 4,997 1.090454 .2868602 1 2 rx5cat1 | 4,997 149.3132 87.18272 2 899 rx5cat2 | 589 190.6655 76.29571 12 340 rx5cat3 | 37 204.0541 27.07597 180 270 rx5cat4 | 25 205 0 205 205 -------------+--------------------------------------------------------- rx5v1c1 | 4,997 115.8463 99.8024 1 899 rx5v1c2 | 589 91.41256 70.11076 1 358 rx5v1c3 | 37 73.75676 25.18311 57 122 rx5v1c4 | 25 57 0 57 57 rx5v2c1 | 4,996 104.4696 105.4721 2 999 -------------+--------------------------------------------------------- rx5v2c2 | 589 104.8014 77.28758 5 340 rx5v2c3 | 37 102.1081 70.21071 65 270 rx5v2c4 | 25 66 0 66 66 rx5v3c1 | 2,958 181.9841 91.73531 59 999 rx5v3c2 | 0 -------------+--------------------------------------------------------- rx5v3c3 | 0 rx5v3c4 | 0 drugid6 | 0 prescr6 | 3,602 1.26874 .5825044 1 3 contsub6 | 3,602 5.806496 .8009519 2 7 -------------+--------------------------------------------------------- comstat6 | 3,602 1.083287 .276354 1 2 rx6cat1 | 3,602 150.3265 84.91979 2 899 rx6cat2 | 445 198.2382 73.49384 12 340 rx6cat3 | 23 205.2609 29.98517 180 270 rx6cat4 | 13 205 0 205 205 -------------+--------------------------------------------------------- rx6v1c1 | 3,602 116.6996 101.2927 1 899 rx6v1c2 | 445 90.70562 64.4098 1 358 rx6v1c3 | 23 80.13043 27.80664 57 122 rx6v1c4 | 13 57 0 57 57 rx6v2c1 | 3,601 104.1983 107.4608 2 999 -------------+--------------------------------------------------------- rx6v2c2 | 445 114.6 84.71121 5 340 rx6v2c3 | 23 100.5652 58.99062 65 270 rx6v2c4 | 13 66 0 66 66 rx6v3c1 | 2,179 179.9238 85.16098 59 999 rx6v3c2 | 0 -------------+--------------------------------------------------------- rx6v3c3 | 0 rx6v3c4 | 0 drugid7 | 0 prescr7 | 2,640 1.277652 .5831671 1 3 contsub7 | 2,640 5.823485 .7538568 2 7 -------------+--------------------------------------------------------- comstat7 | 2,640 1.092045 .2891449 1 2 rx7cat1 | 2,640 152.267 85.09113 2 899 rx7cat2 | 336 199.2262 72.51879 12 340 rx7cat3 | 18 217.1667 38.31641 180 270 rx7cat4 | 7 205 0 205 205 -------------+--------------------------------------------------------- rx7v1c1 | 2,640 116.9602 100.8243 1 899 rx7v1c2 | 336 93.66369 64.83078 1 358 rx7v1c3 | 18 86.88889 25.43016 57 122 rx7v1c4 | 7 57 0 57 57 rx7v2c1 | 2,639 108.7067 113.2905 2 999 -------------+--------------------------------------------------------- rx7v2c2 | 336 116.0536 83.20012 4 340 rx7v2c3 | 18 137.2778 87.27361 65 270 rx7v2c4 | 7 66 0 66 66 rx7v3c1 | 1,548 179.3049 87.42238 59 999 rx7v3c2 | 0 -------------+--------------------------------------------------------- rx7v3c3 | 0 rx7v3c4 | 0 drugid8 | 0 prescr8 | 1,864 1.299356 .6142691 1 3 contsub8 | 1,864 5.805258 .7973078 2 7 -------------+--------------------------------------------------------- comstat8 | 1,864 1.090665 .2872095 1 2 rx8cat1 | 1,864 152.2108 82.04375 2 343 rx8cat2 | 223 196.713 83.55097 12 340 rx8cat3 | 11 218.6364 39.58857 180 270 rx8cat4 | 3 205 0 205 205 -------------+--------------------------------------------------------- rx8v1c1 | 1,864 118.1808 99.90903 1 358 rx8v1c2 | 223 88.08072 67.0019 1 358 rx8v1c3 | 11 92.18182 28.76741 57 122 rx8v1c4 | 3 57 0 57 57 rx8v2c1 | 1,864 109.441 115.5344 2 999 -------------+--------------------------------------------------------- rx8v2c2 | 223 117.7399 92.53232 5 340 rx8v2c3 | 11 127.2727 75.36722 64 270 rx8v2c4 | 3 66 0 66 66 rx8v3c1 | 1,076 181.1608 78.02876 59 341 rx8v3c2 | 0 -------------+--------------------------------------------------------- rx8v3c3 | 0 rx8v3c4 | 0 bioter | 35,105 1.724683 .9250955 1 4 mdsp | 35,105 1.945934 .8892235 1 4 emropd | 35,105 2.541689 .6808614 0 4 -------------+--------------------------------------------------------- edemogo | 35,105 5.169264 3.445286 1 9 ecpoeo | 35,105 5.368466 3.179575 1 9 ewarno | 35,105 6.970175 2.420393 1 9 escripo | 35,105 7.054323 2.308846 1 9 ectoeo | 35,105 5.320553 3.224091 1 9 -------------+--------------------------------------------------------- eordero | 35,105 6.691924 2.710462 1 9 eresulto | 35,105 5.221308 3.38976 1 9 erangeo | 35,105 5.730893 3.242579 1 9 eimgreso | 35,105 5.373907 3.334784 1 9 eimageo | 35,105 6.268395 2.904596 1 9 -------------+--------------------------------------------------------- epnoteso | 35,105 5.303176 3.326121 1 9 ehxfuo | 35,105 6.772739 3.398302 1 9 eremindo | 35,105 6.364934 2.765648 1 9 epubhtho | 35,105 6.240194 3.396565 1 9 enotdiso | 35,105 8.223159 1.727669 1 9 -------------+--------------------------------------------------------- emrnewo | 35,105 2.600256 2.170552 1 9 ccs | 35,105 4.944965 3.290911 1 9 racer | 35,105 1.361658 .5913188 1 3 raceeth | 35,105 1.826378 1.213773 1 7 agedays | 35,105 963.226 171.9385 0 999 -------------+--------------------------------------------------------- ager | 35,105 3.002763 1.473702 1 6 diag1r | 35,105 167563.6 72733.26 100390 900000 diag2r | 35,105 541124.9 368568.5 100380 900000 diag3r | 35,105 731062.3 310722.2 100480 900000 scopwi1r | 35,105 125.2202 835.9297 0 9999 -------------+--------------------------------------------------------- scopwi2r | 35,105 9.902179 237.5253 0 9999 diagsc1r | 35,105 1415.694 3288.847 0 9999 diagsc2r | 35,105 240.9449 1467.54 0 9999 othproc1r | 35,105 717.7014 2378.648 0 9999 othproc2r | 35,105 130.6431 1075.313 0 9999 -------------+--------------------------------------------------------- othproc3r | 35,105 5.347529 207.9979 0 9929 othproc4r | 35,105 1.306253 111.2158 0 9999 whocomp | 35,105 2.417234 1.586371 1 6 settype | 35,105 2 0 2 2 year | 35,105 2006 0 2006 2006 -------------+--------------------------------------------------------- cstratm | 35,105 2.92e+07 9944918 2.01e+07 4.04e+07 cpsum | 35,105 55322.52 49774.02 5 100242 opdwt | 235 11.33191 15.11411 1 79 pctpovr | 35,105 3.037715 1.792778 1 9 hincomer | 35,105 2.759265 1.917752 1 9 -------------+--------------------------------------------------------- pbamorer | 35,105 2.789061 1.922814 1 9 urbanrur | 35,105 2.726364 1.904298 1 9 by Jean Roth , jroth@nber.org , 28 Mar 2016