Willingness to Pay to Shorten Waiting Time for Cataract Surgery

Health Affairs

Volumn 16, Issue 5, 1997, Pages 181-190

  Anderson, Gerard ^b   Black, Charlyn ^b   Dunn, Elaine ^b   Alonso, Jordi ^a   Christian Norregard, Jens ^b   Folmer Anderson, Tavs ^b   Bernth Peterson, Peter ^b  

^a INST MUNIC D INVESTIGACIO MEDICA   (Spain)

^b NONE

Author keywords

[No Author keywords available]

Indexed keywords

AGED; ARTICLE; ATTITUDE TO HEALTH; CANADA; CATARACT EXTRACTION; DENMARK; ECONOMICS; FEMALE; FINANCIAL MANAGEMENT; HOSPITAL ADMISSION; HUMAN; MALE; PATIENT SATISFACTION; QUESTIONNAIRE; SPAIN; STATISTICS; TAX;

AGED; ATTITUDE TO HEALTH; CANADA; CATARACT EXTRACTION; DENMARK; FEMALE; FINANCING, PERSONAL; HUMANS; INCOME TAX; MALE; PATIENT SATISFACTION; QUESTIONNAIRES; SPAIN; WAITING LISTS;

EID: 0347738499     PISSN: 02782715     EISSN: None     Source Type: Journal    
DOI: 10.1377/hlthaff.16.5.181     Document Type: Article

References (44)

1. C.D. Naylor, "A Different View of Queues in Ontario," Health Affairs (Fall 1991): 110-128; S.J. Katz, H.F. Mizgala, and H.G. Welch, "British Columbia Sends Patients to Seattle for Coronary Artery Surgery," Journal of the American Medical Association 266, no. 8 (1991): 1108-1111; J.G. Cullis and P.R. Jones, "National Health Service Waiting Lists: A Discussion of Competing Explanations and a Policy Proposal," Journal of Health Economics 4 (1985): 119-135; and C.E.B. Frost and B.J. Francis, "Clinical Decision Making: A Study of General Surgery within Trent RHA," Social Science and Medicine 13A (1976): 193-198.
2. C.D. Naylor, "A Different View of Queues in Ontario," Health Affairs (Fall 1991): 110-128; S.J. Katz, H.F. Mizgala, and H.G. Welch, "British Columbia Sends Patients to Seattle for Coronary Artery Surgery," Journal of the American Medical Association 266, no. 8 (1991): 1108-1111; J.G. Cullis and P.R. Jones, "National Health Service Waiting Lists: A Discussion of Competing Explanations and a Policy Proposal," Journal of Health Economics 4 (1985): 119-135; and C.E.B. Frost and B.J. Francis, "Clinical Decision Making: A Study of General Surgery within Trent RHA," Social Science and Medicine 13A (1976): 193-198.
3. C.D. Naylor, "A Different View of Queues in Ontario," Health Affairs (Fall 1991): 110-128; S.J. Katz, H.F. Mizgala, and H.G. Welch, "British Columbia Sends Patients to Seattle for Coronary Artery Surgery," Journal of the American Medical Association 266, no. 8 (1991): 1108-1111; J.G. Cullis and P.R. Jones, "National Health Service Waiting Lists: A Discussion of Competing Explanations and a Policy Proposal," Journal of Health Economics 4 (1985): 119-135; and C.E.B. Frost and B.J. Francis, "Clinical Decision Making: A Study of General Surgery within Trent RHA," Social Science and Medicine 13A (1976): 193-198.
4. C.D. Naylor, "A Different View of Queues in Ontario," Health Affairs (Fall 1991): 110-128; S.J. Katz, H.F. Mizgala, and H.G. Welch, "British Columbia Sends Patients to Seattle for Coronary Artery Surgery," Journal of the American Medical Association 266, no. 8 (1991): 1108-1111; J.G. Cullis and P.R. Jones, "National Health Service Waiting Lists: A Discussion of Competing Explanations and a Policy Proposal," Journal of Health Economics 4 (1985): 119-135; and C.E.B. Frost and B.J. Francis, "Clinical Decision Making: A Study of General Surgery within Trent RHA," Social Science and Medicine 13A (1976): 193-198.
5. C.M. Lindsay and B. Feigenbaum, "Rationing by Waiting Lists," American Economic Review 74, no. 3 (1984): 404-417; A. Street and S. Duckett, "Are Waiting Lists Inevitable?" Health Policy 36 (1996): 1-15; M. Hanning, "Maximum Waiting Time Guarantee: An Attempt to Reduce Waiting Lists in Sweden," Health Policy 36 (1996): 17-35; C.D. Naylor et al., "Queuing for Coronary Surgery during Severe Supply-Demand Mismatch in a Canadian Referral Centre: A Case Study of Implicit Rationing," Social Science and Medicine 37, no. 1 (1993): 61-67; S. Frankel and R. West, eds., Rationing and Rationality in the National Health Service: The Persistence of Waiting Lists, Economic Issues in Health Care (London: Macmillan, 1993), 157-170; R. Mulgan and R.L. Logan, "The Coronary Bypass Waiting List: A Social Evaluation," New Zealand Medical Journal 103 (1990): 371-372; C.D. Naylor et al., "Waiting for Coronary Revascularization in Toronto: A Year's Experience with a Regional Referral Office," Canadian Medical Association Journal 149, no. 7 (1993): 955-962; and C.D. Naylor, K. Sykora, and S.B. Jaglal, "Waiting for Coronary Artery Bypass Surgery: Population-Based Study of 8,517 Consecutive Patients in Ontario, Canada," Lancet 346, no. 8990 (1995): 1605-1609.
6. C.M. Lindsay and B. Feigenbaum, "Rationing by Waiting Lists," American Economic Review 74, no. 3 (1984): 404-417; A. Street and S. Duckett, "Are Waiting Lists Inevitable?" Health Policy 36 (1996): 1-15; M. Hanning, "Maximum Waiting Time Guarantee: An Attempt to Reduce Waiting Lists in Sweden," Health Policy 36 (1996): 17-35; C.D. Naylor et al., "Queuing for Coronary Surgery during Severe Supply-Demand Mismatch in a Canadian Referral Centre: A Case Study of Implicit Rationing," Social Science and Medicine 37, no. 1 (1993): 61-67; S. Frankel and R. West, eds., Rationing and Rationality in the National Health Service: The Persistence of Waiting Lists, Economic Issues in Health Care (London: Macmillan, 1993), 157-170; R. Mulgan and R.L. Logan, "The Coronary Bypass Waiting List: A Social Evaluation," New Zealand Medical Journal 103 (1990): 371-372; C.D. Naylor et al., "Waiting for Coronary Revascularization in Toronto: A Year's Experience with a Regional Referral Office," Canadian Medical Association Journal 149, no. 7 (1993): 955-962; and C.D. Naylor, K. Sykora, and S.B. Jaglal, "Waiting for Coronary Artery Bypass Surgery: Population-Based Study of 8,517 Consecutive Patients in Ontario, Canada," Lancet 346, no. 8990 (1995): 1605-1609.
7. C.M. Lindsay and B. Feigenbaum, "Rationing by Waiting Lists," American Economic Review 74, no. 3 (1984): 404-417; A. Street and S. Duckett, "Are Waiting Lists Inevitable?" Health Policy 36 (1996): 1-15; M. Hanning, "Maximum Waiting Time Guarantee: An Attempt to Reduce Waiting Lists in Sweden," Health Policy 36 (1996): 17-35; C.D. Naylor et al., "Queuing for Coronary Surgery during Severe Supply-Demand Mismatch in a Canadian Referral Centre: A Case Study of Implicit Rationing," Social Science and Medicine 37, no. 1 (1993): 61-67; S. Frankel and R. West, eds., Rationing and Rationality in the National Health Service: The Persistence of Waiting Lists, Economic Issues in Health Care (London: Macmillan, 1993), 157-170; R. Mulgan and R.L. Logan, "The Coronary Bypass Waiting List: A Social Evaluation," New Zealand Medical Journal 103 (1990): 371-372; C.D. Naylor et al., "Waiting for Coronary Revascularization in Toronto: A Year's Experience with a Regional Referral Office," Canadian Medical Association Journal 149, no. 7 (1993): 955-962; and C.D. Naylor, K. Sykora, and S.B. Jaglal, "Waiting for Coronary Artery Bypass Surgery: Population-Based Study of 8,517 Consecutive Patients in Ontario, Canada," Lancet 346, no. 8990 (1995): 1605-1609.
8. C.M. Lindsay and B. Feigenbaum, "Rationing by Waiting Lists," American Economic Review 74, no. 3 (1984): 404-417; A. Street and S. Duckett, "Are Waiting Lists Inevitable?" Health Policy 36 (1996): 1-15; M. Hanning, "Maximum Waiting Time Guarantee: An Attempt to Reduce Waiting Lists in Sweden," Health Policy 36 (1996): 17-35; C.D. Naylor et al., "Queuing for Coronary Surgery during Severe Supply-Demand Mismatch in a Canadian Referral Centre: A Case Study of Implicit Rationing," Social Science and Medicine 37, no. 1 (1993): 61-67; S. Frankel and R. West, eds., Rationing and Rationality in the National Health Service: The Persistence of Waiting Lists, Economic Issues in Health Care (London: Macmillan, 1993), 157-170; R. Mulgan and R.L. Logan, "The Coronary Bypass Waiting List: A Social Evaluation," New Zealand Medical Journal 103 (1990): 371-372; C.D. Naylor et al., "Waiting for Coronary Revascularization in Toronto: A Year's Experience with a Regional Referral Office," Canadian Medical Association Journal 149, no. 7 (1993): 955-962; and C.D. Naylor, K. Sykora, and S.B. Jaglal, "Waiting for Coronary Artery Bypass Surgery: Population-Based Study of 8,517 Consecutive Patients in Ontario, Canada," Lancet 346, no. 8990 (1995): 1605-1609.
9. C.M. Lindsay and B. Feigenbaum, "Rationing by Waiting Lists," American Economic Review 74, no. 3 (1984): 404-417; A. Street and S. Duckett, "Are Waiting Lists Inevitable?" Health Policy 36 (1996): 1-15; M. Hanning, "Maximum Waiting Time Guarantee: An Attempt to Reduce Waiting Lists in Sweden," Health Policy 36 (1996): 17-35; C.D. Naylor et al., "Queuing for Coronary Surgery during Severe Supply-Demand Mismatch in a Canadian Referral Centre: A Case Study of Implicit Rationing," Social Science and Medicine 37, no. 1 (1993): 61-67; S. Frankel and R. West, eds., Rationing and Rationality in the National Health Service: The Persistence of Waiting Lists, Economic Issues in Health Care (London: Macmillan, 1993), 157-170; R. Mulgan and R.L. Logan, "The Coronary Bypass Waiting List: A Social Evaluation," New Zealand Medical Journal 103 (1990): 371-372; C.D. Naylor et al., "Waiting for Coronary Revascularization in Toronto: A Year's Experience with a Regional Referral Office," Canadian Medical Association Journal 149, no. 7 (1993): 955-962; and C.D. Naylor, K. Sykora, and S.B. Jaglal, "Waiting for Coronary Artery Bypass Surgery: Population-Based Study of 8,517 Consecutive Patients in Ontario, Canada," Lancet 346, no. 8990 (1995): 1605-1609.
10. C.M. Lindsay and B. Feigenbaum, "Rationing by Waiting Lists," American Economic Review 74, no. 3 (1984): 404-417; A. Street and S. Duckett, "Are Waiting Lists Inevitable?" Health Policy 36 (1996): 1-15; M. Hanning, "Maximum Waiting Time Guarantee: An Attempt to Reduce Waiting Lists in Sweden," Health Policy 36 (1996): 17-35; C.D. Naylor et al., "Queuing for Coronary Surgery during Severe Supply-Demand Mismatch in a Canadian Referral Centre: A Case Study of Implicit Rationing," Social Science and Medicine 37, no. 1 (1993): 61-67; S. Frankel and R. West, eds., Rationing and Rationality in the National Health Service: The Persistence of Waiting Lists, Economic Issues in Health Care (London: Macmillan, 1993), 157-170; R. Mulgan and R.L. Logan, "The Coronary Bypass Waiting List: A Social Evaluation," New Zealand Medical Journal 103 (1990): 371-372; C.D. Naylor et al., "Waiting for Coronary Revascularization in Toronto: A Year's Experience with a Regional Referral Office," Canadian Medical Association Journal 149, no. 7 (1993): 955-962; and C.D. Naylor, K. Sykora, and S.B. Jaglal, "Waiting for Coronary Artery Bypass Surgery: Population-Based Study of 8,517 Consecutive Patients in Ontario, Canada," Lancet 346, no. 8990 (1995): 1605-1609.
11. C.M. Lindsay and B. Feigenbaum, "Rationing by Waiting Lists," American Economic Review 74, no. 3 (1984): 404-417; A. Street and S. Duckett, "Are Waiting Lists Inevitable?" Health Policy 36 (1996): 1-15; M. Hanning, "Maximum Waiting Time Guarantee: An Attempt to Reduce Waiting Lists in Sweden," Health Policy 36 (1996): 17-35; C.D. Naylor et al., "Queuing for Coronary Surgery during Severe Supply-Demand Mismatch in a Canadian Referral Centre: A Case Study of Implicit Rationing," Social Science and Medicine 37, no. 1 (1993): 61-67; S. Frankel and R. West, eds., Rationing and Rationality in the National Health Service: The Persistence of Waiting Lists, Economic Issues in Health Care (London: Macmillan, 1993), 157-170; R. Mulgan and R.L. Logan, "The Coronary Bypass Waiting List: A Social Evaluation," New Zealand Medical Journal 103 (1990): 371-372; C.D. Naylor et al., "Waiting for Coronary Revascularization in Toronto: A Year's Experience with a Regional Referral Office," Canadian Medical Association Journal 149, no. 7 (1993): 955-962; and C.D. Naylor, K. Sykora, and S.B. Jaglal, "Waiting for Coronary Artery Bypass Surgery: Population-Based Study of 8,517 Consecutive Patients in Ontario, Canada," Lancet 346, no. 8990 (1995): 1605-1609.
12. C.M. Lindsay and B. Feigenbaum, "Rationing by Waiting Lists," American Economic Review 74, no. 3 (1984): 404-417; A. Street and S. Duckett, "Are Waiting Lists Inevitable?" Health Policy 36 (1996): 1-15; M. Hanning, "Maximum Waiting Time Guarantee: An Attempt to Reduce Waiting Lists in Sweden," Health Policy 36 (1996): 17-35; C.D. Naylor et al., "Queuing for Coronary Surgery during Severe Supply-Demand Mismatch in a Canadian Referral Centre: A Case Study of Implicit Rationing," Social Science and Medicine 37, no. 1 (1993): 61-67; S. Frankel and R. West, eds., Rationing and Rationality in the National Health Service: The Persistence of Waiting Lists, Economic Issues in Health Care (London: Macmillan, 1993), 157-170; R. Mulgan and R.L. Logan, "The Coronary Bypass Waiting List: A Social Evaluation," New Zealand Medical Journal 103 (1990): 371-372; C.D. Naylor et al., "Waiting for Coronary Revascularization in Toronto: A Year's Experience with a Regional Referral Office," Canadian Medical Association Journal 149, no. 7 (1993): 955-962; and C.D. Naylor, K. Sykora, and S.B. Jaglal, "Waiting for Coronary Artery Bypass Surgery: Population-Based Study of 8,517 Consecutive Patients in Ontario, Canada," Lancet 346, no. 8990 (1995): 1605-1609.
13. G.C. Morrison and M. Gyldmark, "Appraising the Use of Contingent Valuation," Health Economics 1 (1992): 233-243; and D.S. Brookshire et al., "Valuing Public Goods: A Comparison of Survey and Hedonic Approaches," The American Economic Review 72, no. 1 (1982): 165-177.
14. G.C. Morrison and M. Gyldmark, "Appraising the Use of Contingent Valuation," Health Economics 1 (1992): 233-243; and D.S. Brookshire et al., "Valuing Public Goods: A Comparison of Survey and Hedonic Approaches," The American Economic Review 72, no. 1 (1982): 165-177.
15. All seventeen hospital departments agreed to participate in Denmark; all practicing ophthalmologists were asked to participate in Manitoba, and seven of twelve agreed to participate; and a random sample of public hospital departments were recruited in Barcelona.
16. A total of 546 patients were contacted and 501 signed an informed consent agreeing to participate in the study. The sample size for this paper was 464 because we required the patients to remain in the study for a four-month follow-up to be included in this data set.
17. Naylor et al., "Queuing for Coronary Surgery;" Mulgan and Logan, "The Coronary Bypass Waiting List;" Naylor et al., "Waiting for Coronary Revascularization in Toronto;" and C.D. Naylor et al., "Placing Patients in the Queue for Coronary Surgery: How Do Age and Work Status Affect Consultants' Decisions?" Journal of General Internal Medicine 7 (1992): 492-498.
18. Naylor et al., "Queuing for Coronary Surgery;" Mulgan and Logan, "The Coronary Bypass Waiting List;" Naylor et al., "Waiting for Coronary Revascularization in Toronto;" and C.D. Naylor et al., "Placing Patients in the Queue for Coronary Surgery: How Do Age and Work Status Affect Consultants' Decisions?" Journal of General Internal Medicine 7 (1992): 492-498.
19. Naylor et al., "Queuing for Coronary Surgery;" Mulgan and Logan, "The Coronary Bypass Waiting List;" Naylor et al., "Waiting for Coronary Revascularization in Toronto;" and C.D. Naylor et al., "Placing Patients in the Queue for Coronary Surgery: How Do Age and Work Status Affect Consultants' Decisions?" Journal of General Internal Medicine 7 (1992): 492-498.
20. Naylor et al., "Queuing for Coronary Surgery;" Mulgan and Logan, "The Coronary Bypass Waiting List;" Naylor et al., "Waiting for Coronary Revascularization in Toronto;" and C.D. Naylor et al., "Placing Patients in the Queue for Coronary Surgery: How Do Age and Work Status Affect Consultants' Decisions?" Journal of General Internal Medicine 7 (1992): 492-498.
21. E.P. Steinberg et al., "The VF-14 Index: An Index of Functional Impairment in Patients with Cataract," Archives of Ophthalmology 112 (1994): 630-638. VF-14 scores potentially range from 0 to 100, with lower scores indicating poorer functional ability.
22. The six cataract-related symptoms are distorted vision, glare or halo, blurry vision, brightness distortion, color distortion, and recent worsening of vision. The number of symptoms and their associated degree of bother, from "a little" to "very bothered," were summed for each patient, resulting in a range of scores from 0 (no symptoms) to 18 (very bothered by all six symptoms).
23. G. Anderson et al., "Analyzing Health Outcomes through International Comparisons," Medical Care 32, no. 5 (1994): 526-534.
24. Compared with respondents from Manitoba and Denmark, respondents from Barcelona were more likely to be younger, be male, have a limited educational experience, and have lower incomes; were less likely to live alone and to work or volunteer outside of their home; and had worse measures of visual acuity and visual functioning. Respondents from Denmark and Manitoba demonstrated greater similarity in their characteristics; however, Danish respondents were more likely to live alone and have higher incomes, while respondents from Manitoba were more likely to have a history of other eye disease and to have a higher level of education.
25. The specific wording of the question is, "Do you think people should pay higher taxes in order to eliminate the waiting times for surgery?"
26. The specific wording is, "If patients had the opportunity to pay out of pocket to reduce their waiting times for cataract surgery, do you think you would have chosen to pay $X (per eye) to reduce your waiting time to less than one month?"
27. We used 1993 purchasing power parities to convert the currencies of other nations to U.S. dollars. Organization for Economic and Community Development, OECD Health Data: Comparative Analysis of Health Systems, 1995 (Paris: OECD, 1995), 1-136.
28. We chose to center the dollar-threshold questions on the usual cost of obtaining cataract surgery instead of the more conventional technique used in willingness-to-pay questionnaires of starting at a very low rate or very high rate and trying to elicit a crossover point. This was done to minimize the number of questions and to make the price seem more realistic. We recognize that this could have introduced some starting-point bias.
29. The price elasticity was statistically significant (p = 0.002) for Manitoba and not statistically significant for Barcelona (p = 0.709) or Denmark (p = 0.325).
30. None of the values was statistically significant at the p < 0.05 level.
31. Full regression results are available from the authors. Contact Gerard Anderson, Director, Center for Hospital Finance and Management, Room 300, Hampton House, 624 North Broadway, The Johns Hopkins University, Baltimore, MD 21205. All of the variables are entered as continuous variables except when explicitly defined as a categorical variable.
32. C. Borrell, I. Pasarin, and A. Plansencia, Enquesta de Salut de Barcelona, 1992-1993 (Health Interview of Barcelona) (Barcelona: Estadistiques de Salut no. 23, Ajuntament de Barcelona, 1995).
33. Ibid.; and H. Sigmund and B. Danneskiold-Samsoe, Operation af grå stær på sygehus og i praksis (DSI Report 92.01, Copenhagen, Denmark).
34. Ibid.; and H. Sigmund and B. Danneskiold-Samsoe, Operation af grå stær på sygehus og i praksis (DSI Report 92.01, Copenhagen, Denmark).
35. Mulgan and Logan, "The Coronary Bypass Waiting List;" Naylor et al., "Waiting for Coronary Revascularization in Toronto;" and Naylor et al., "Waiting for Coronary Artery Bypass Surgery."
36. Mulgan and Logan, "The Coronary Bypass Waiting List;" Naylor et al., "Waiting for Coronary Revascularization in Toronto;" and Naylor et al., "Waiting for Coronary Artery Bypass Surgery."
37. Mulgan and Logan, "The Coronary Bypass Waiting List;" Naylor et al., "Waiting for Coronary Revascularization in Toronto;" and Naylor et al., "Waiting for Coronary Artery Bypass Surgery."
38. D.M. Berwick and M.C. Weinstein, "What Do Patients Value? Willingness to Pay for Ultrasound in Normal Pregnancy," Medical Care 23, no. 7 (1985): 881-893; M. Johanneson, B. Jonsson, and L. Borgquist, "Willingness to Pay for Antihypertensive Therapy: Results of a Swedish Pilot Study," Journal of Health Economics 10 (1991): 461-474; B. O'Brien and J.L. Viramontes, "Willingness to Pay: A Valid and Reliable Measure of Health State Preference?" Medical Decision Making (July-September 1994): 289-297; D. McFadden, "Contingent Valuation and Social Choice," American Journal of Agriculture and Economics 76 (1994): 689-708; and T.A. Cameron and M.D. James, "Estimating Willingness to Pay from Survey Data: An Alternative Pre-Test Market Evaluation Procedure," Journal of Marketing Research 29 (1987): 389-395.
39. D.M. Berwick and M.C. Weinstein, "What Do Patients Value? Willingness to Pay for Ultrasound in Normal Pregnancy," Medical Care 23, no. 7 (1985): 881-893; M. Johanneson, B. Jonsson, and L. Borgquist, "Willingness to Pay for Antihypertensive Therapy: Results of a Swedish Pilot Study," Journal of Health Economics 10 (1991): 461-474; B. O'Brien and J.L. Viramontes, "Willingness to Pay: A Valid and Reliable Measure of Health State Preference?" Medical Decision Making (July-September 1994): 289-297; D. McFadden, "Contingent Valuation and Social Choice," American Journal of Agriculture and Economics 76 (1994): 689-708; and T.A. Cameron and M.D. James, "Estimating Willingness to Pay from Survey Data: An Alternative Pre-Test Market Evaluation Procedure," Journal of Marketing Research 29 (1987): 389-395.
40. D.M. Berwick and M.C. Weinstein, "What Do Patients Value? Willingness to Pay for Ultrasound in Normal Pregnancy," Medical Care 23, no. 7 (1985): 881-893; M. Johanneson, B. Jonsson, and L. Borgquist, "Willingness to Pay for Antihypertensive Therapy: Results of a Swedish Pilot Study," Journal of Health Economics 10 (1991): 461-474; B. O'Brien and J.L. Viramontes, "Willingness to Pay: A Valid and Reliable Measure of Health State Preference?" Medical Decision Making (July-September 1994): 289-297; D. McFadden, "Contingent Valuation and Social Choice," American Journal of Agriculture and Economics 76 (1994): 689-708; and T.A. Cameron and M.D. James, "Estimating Willingness to Pay from Survey Data: An Alternative Pre-Test Market Evaluation Procedure," Journal of Marketing Research 29 (1987): 389-395.
41. D.M. Berwick and M.C. Weinstein, "What Do Patients Value? Willingness to Pay for Ultrasound in Normal Pregnancy," Medical Care 23, no. 7 (1985): 881-893; M. Johanneson, B. Jonsson, and L. Borgquist, "Willingness to Pay for Antihypertensive Therapy: Results of a Swedish Pilot Study," Journal of Health Economics 10 (1991): 461-474; B. O'Brien and J.L. Viramontes, "Willingness to Pay: A Valid and Reliable Measure of Health State Preference?" Medical Decision Making (July-September 1994): 289-297; D. McFadden, "Contingent Valuation and Social Choice," American Journal of Agriculture and Economics 76 (1994): 689-708; and T.A. Cameron and M.D. James, "Estimating Willingness to Pay from Survey Data: An Alternative Pre-Test Market Evaluation Procedure," Journal of Marketing Research 29 (1987): 389-395.
42. D.M. Berwick and M.C. Weinstein, "What Do Patients Value? Willingness to Pay for Ultrasound in Normal Pregnancy," Medical Care 23, no. 7 (1985): 881-893; M. Johanneson, B. Jonsson, and L. Borgquist, "Willingness to Pay for Antihypertensive Therapy: Results of a Swedish Pilot Study," Journal of Health Economics 10 (1991): 461-474; B. O'Brien and J.L. Viramontes, "Willingness to Pay: A Valid and Reliable Measure of Health State Preference?" Medical Decision Making (July-September 1994): 289-297; D. McFadden, "Contingent Valuation and Social Choice," American Journal of Agriculture and Economics 76 (1994): 689-708; and T.A. Cameron and M.D. James, "Estimating Willingness to Pay from Survey Data: An Alternative Pre-Test Market Evaluation Procedure," Journal of Marketing Research 29 (1987): 389-395.
43. See Note 11.
44. R.C. Bishop and T.A. Heberlein, "Measuring Value of Extramarket Goods: Are Indirect Measures Biased?" American Journal of Agriculture and Economics 22, no. 3 (1979): 926-930.