Do State Bans of Most-Favored-Nation Contract Clauses Restrain Price Growth? Evidence From Hospital Prices.

Policy Points Looking for a way to curtail market power abuses in health care and rein in prices, 20 states have restricted most-favored-nation (MFN) clauses in some health care contracts. Little is known as to whether restrictions on MFN clauses slow health care price growth. Banning MFN clauses between insurers and hospitals in highly concentrated insurer markets seems to improve competition and lead to lower hospital prices. CONTEXT: Most-favored-nation (MFN) contract clauses have recently garnered attention from both Congress and state legislatures looking for ways to curtail market power abuses in health care and rein in prices. In health care, a typical MFN contract clause is stipulated by the insurer and requires a health care provider to grant the insurer the lowest (i.e., the most-favored) price among the insurers it contracts with. As of August 2020, 20 states restrict the use of MFN clauses in health care contracts (19 states ban their use in at least some health care contracts), with 8 states prohibiting their use between 2010 and 2016. METHODS: Using event study and difference-in-differences research designs, we compared prices for a standardized hospital admission in states that banned MFN clauses between 2010 and 2016 with standardized hospital admission prices in states without MFN bans. FINDINGS: Our results show that bans on MFN clauses reduced hospital price growth in metropolitan statistical areas (MSAs) with highly concentrated insurer markets. Specifically, we found that mean hospital prices in MSAs with highly concentrated insurer markets would have been $472 (2.8%) lower in 2016 had the MSAs been in states that banned MFN clauses in 2010. In 2016, the population in our sample that resided in MSAs with highly concentrated insurer markets was just under 75 million (23% of the US population). Hence, banning MFN clauses in all MSAs in our sample with highly concentrated insurer markets in 2010 would have generated savings on hospital expenditures in the range of $2.4 billion per year. CONCLUSIONS: Our empirical findings suggest banning MFN clauses between insurers and providers in highly concentrated insurer markets would improve competition and lead to lower prices and expenditures.

Forecasting imbalances in the global health labor market and devising policy responses.

BACKGROUND: The High-Level Commission on Health Employment and Economic Growth released its report to the United Nations Secretary-General in September 2016. It makes important recommendations that are based on estimates of over 40 million new health sector jobs by 2030 in mostly high- and middle-income countries and a needs-based shortage of 18 million, mostly in low- and middle-income countries. This paper shows how these key findings were developed, the global policy dilemmas they raise, and relevant policy solutions. METHODS: Regression analysis is used to produce estimates of health worker need, demand, and supply. Projections of health worker need, demand, and supply in 2030 are made under the assumption that historical trends continue into the future. RESULTS: To deliver essential health services required for the universal health coverage target of the Sustainable Development Goal 3, there will be a need for almost 45 million health workers in 2013 which is projected to reach almost 53 million in 2030 (across 165 countries). This results in a needs-based shortage of almost 17 million in 2013. The demand-based results suggest a projected demand of 80 million health workers by 2030. CONCLUSIONS: Demand-based analysis shows that high- and middle-income countries will have the economic capacity to employ tens of millions additional health workers, but they could face shortages due to supply not keeping up with demand. By contrast, low-income countries will face both low demand for and supply of health workers. This means that even if countries are able to produce additional workers to meet the need threshold, they may not be able to employ and retain these workers without considerably higher economic growth, especially in the health sector.

Nuclear transfer alters placental gene expression and associated histone modifications of the placental-specific imprinted gene pleckstrin homology-like domain, family A, member 2 (PHLDA2) in cattle.

Abnormal placental development is frequent in nuclear transfer (NT) pregnancies and is likely to be associated with altered epigenetic reprogramming. In the present study, fetal and placental measurements were taken on Day 60 of gestation in cows with pregnancies produced by AI, IVF and NT. Placentas were collected and subjected to histological evaluation, the expression of genes important in trophoblast differentiation and expression of the placental imprinted gene pleckstrin homology-like domain, family A, member 2 (PHLDA2), as well as chromatin immunoprecipitation (ChIP) for histone marks within the promoter of PHLDA2. Fewer binucleated cells were observed in NT cotyledons, followed by IVF and AI cotyledons (P<0.05). Expression of heart and neural crest derivatives expressed 1 (HAND1), placental lactogen (PL), pregnancy-associated glycoprotein 9 (PAG-9) and PHLDA2 was elevated in NT cotyledons compared with AI cotyledons. Expression of PHLDA2 was higher in IVF than AI samples (P<0.05). ChIP revealed an increase in the permissive mark dimethylation of lysine 4 on histone H3 (H3K4me2), surprisingly associated with the silent allele of PHLDA2, and a decrease in the inhibitory mark H3K9me2 in NT samples. Thus, genes critical for placental development were altered in NT placentas, including an imprinted gene. Allele-specific changes in the permissive histone mark in the PHLDA2 promoter indicate misregulation of imprinting in clones. Abnormal trophoblast differentiation could have resulted in lower numbers of binucleated cells following NT. These results suggest that the altered expression of imprinted genes associated with NT are also caused by changes in histone modifications.

New evidence on the impacts of cross-market hospital mergers on commercial prices and measures of quality.

OBJECTIVE: To examine the impact of "cross-market" hospital mergers on prices and quality and the extent to which serial acquisitions contribute to any measured effects. DATA SOURCES: 2009-2017 commercial claims from the Health Care Cost Institute (HCCI) and quality measures from Hospital Compare. STUDY DESIGN: Event study models in which the treated group consisted of hospitals that acquired hospitals further than 50 miles, and the control group was hospitals that were not part of any merger activity (as a target or acquirer) during the study period. DATA EXTRACTION METHODS: We extracted data for 214 treated hospitals and 955 control hospitals. PRINCIPAL FINDINGS: Six years after acquisition, cross-market hospital mergers had increased acquirer prices by 12.9% (CI: 0.6%-26.6%) relative to control hospitals, but had no discernible impact on mortality and readmission rates for heart failure, heart attacks and pneumonia. For serial acquirers, the price effect increased to 16.3% (CI: 4.8%-29.1%). For all acquisitions, the price effect was 21.8% (CI: 4.6%-41.7%) when the target's market share was greater than the acquirer's market share versus 9.7% (CI: -0.5% to 20.9%) when the opposite was true. The magnitude of the price effect was similar for out-of-state and in-state cross-market mergers. CONCLUSIONS: Additional evidence on the price and quality effects of cross-market mergers is needed at a time when over half of recent hospital mergers have been cross-market. To date, no hospital mergers have been challenged by the Federal Trade Commission on cross-market grounds. Our study is the third to find a positive price effect associated with cross-market mergers and the first to show no quality effect and how serial acquisitions contribute to the price effect. More research is needed to identify the mechanism behind the price effects we observe and analyze price effect heterogeneity.

Association Between a Capitated, Low-cost, County-Based Public Health Insurance Option and Affordable Care Act Premium Growth in California.

Importance: Empirical evidence is needed on how a capitated, risk-based county plan performs as a viable public option in the Affordable Care Act (ACA) Marketplace in California. Objective: To estimate whether LA Care-a capitated, county-based public option and California's largest public insurer-was associated with health insurance premium growth in the Los Angeles (LA) regions of Covered California (CC), the ACA exchange in California. Design, Setting, and Participants: This economic evaluation used ACA silver plan premium data within the 19 CC regions. Difference-in-differences and event study models used data on plan-level premiums from Health Insurance Exchange Compare for years 2014 to 2022 to estimate the association between LA Care and ACA premium growth in LA. Exposures: The intervention was LA Care becoming the lowest-cost health plan on the ACA exchange in 2018. The treatment group included the East and West LA regions, and the control group included the remaining 17 CC regions. Main Outcomes and Measures: The main outcome variable was annual premium growth of plans on CC from 2014 to 2022. Results: Using 504 plan-level observations for 2014 to 2022, ACA premium growth in LA declined by 4.8% after LA Care became the lowest-cost health plan on the exchange in 2018 (coefficient estimate, -0.048; SE, 0.022; 95% CI, -0.093 to -0.002). Savings due to lower premium growth from 2019 to 2022 were calculated to be $345 million, with approximately 70% of the savings ($242 million) going to the federal government. Conclusions and Relevance: In this economic evaluation, LA Care was associated with lower premium growth of other health insurance plans in the LA regions of CC, with the majority of savings going to the federal government. California could have captured these savings if it had applied for and received a State Innovation Waiver under section 1332 of the ACA. LA Care may be a viable public option with the potential to be expanded across California through the state's 16 other county-based health plans.

The Rise Of Cross-Market Hospital Systems And Their Market Power In The US.

Although hospital consolidation within markets has been well documented, consolidation across markets has not, even though economic theory predicts-and evidence is emerging-that cross-market hospital systems raise prices by exerting market power across markets when negotiating with common customers (primarily insurers). This study analyzes hospital systems using the American Hospital Association Annual Survey Database and defines hospital geographic markets as commuting zones that link workers to places of employment. The share of community hospitals in the US that were part of hospital systems increased from 10 percent in 1970 to 67 percent in 2019, resulting in 3,436 hospitals within 368 systems in 2019. Of these systems, 216 (59 percent) owned hospitals in multiple commuting zones, in part because 55 percent of the 1,500 hospitals targeted for a merger or acquisition between 2010 and 2019 were located in a different commuting zone than the acquirer. Based on market-power differences among hospitals in systems, the number of systems in urban commuting zones that could potentially exert enhanced cross-market power increased from thirty-seven systems in 2009 to fifty-seven systems in 2019, an increase of 54 percent. The increase in cross-market hospital systems warrants concern and scrutiny because of the potential anticompetitive impact of hospital systems exerting market power across markets in negotiations with common customers.

Reproductive and epigenetic outcomes associated with aging mouse oocytes.

Female aging entails a decline in fertility in mammals, manifested by reduced oocyte reserves and poor oocyte quality accompanied by chromosomal anomalies and reduced litter size. In addition to compromised genetic integrity, recent studies suggest that epigenetic mechanisms may be altered in aging oocytes, with age affecting the expression of DNA methyltransferases, which catalyze the important epigenetic modification, DNA methylation. Loss of DNA methylation patterns, most notably for imprinted genes, is lethal to mouse embryos. To investigate how maternal age affects embryonic development and underlying DNA methylation patterns, young and aged C57BL/6 females were mated with C57BL/6 or C57BL/6(CAST7) males to allow for the identification of parental alleles; resulting blastocysts and mid-gestation embryos and placentas were evaluated. Although pregnancy, ovulation and implantation rates were similar between age groups, an age-related increase in resorption sites, morphological abnormalities and delayed development was found. Interestingly, placental morphology was also perturbed by aging, with elevated numbers of trophoblast giant cells in aged pregnancies. Normal monoallelic expression of the imprinted genes H19 and Snrpn was unaltered in blastocysts from aged females. We failed to observe any age-related changes in methylation of the differentially methylated regions of imprinted genes Snrpn, Kcnq1ot1, U2af1-rs1, Peg1, Igf2r and H19. Restriction Landmark Genome Scanning showed no significant differences in genome-wide DNA methylation in embryos and placentas, regardless of maternal age. Our findings demonstrate that maternal age affects post-implantation embryo and placental development; however embryos capable of developing to mid-gestation appear to undergo normal acquisition and maintenance of DNA methylation patterning.

Expanding Medical Education and Task Shifting Comment on "Doctor Retention: A Cross-sectional Study of How Ireland Has Been Losing the Battle".

Brugha et al provide convincing evidence that Ireland stills need to overcome many hurdles, including poor training and working experiences in Irish hospitals, before it can significantly improve its record on doctor retention. The findings reported by Brugha et al are particularly disappointing in light of the fact that Ireland implemented a doctor retention strategy in early 2015. Ultimately, doctor retention is important because it can help alleviate the health workforce shortages that many countries face currently and that are projected to worsen over the next decade. The purpose of this commentary is to highlight two additional strategies for alleviating health workforce shortages - expanding medical education and task shifting.

Physician Compensation In Physician-Owned And Hospital-Owned Practices.

Physician practices are increasingly being acquired by hospitals and health systems. Despite evidence that this type of vertical integration is profitable for hospitals, the association between these acquisitions and the incomes of physicians in the acquired practices is unknown. We combined national survey data on physician practice ownership with data on physician income to examine whether hospital or health system ownership of physician practices was associated with differences in physician income during 2014-18. During the study period, hospital and health system ownership of physician practices increased by 89.2 percent, from 24.1 percent to 45.6 percent of all physicians in our sample. Among physician practices overall, vertical integration with hospitals or health systems was associated with, on average, 0.8 percent lower income compared with independent physicians after multivariable adjustment. In analyses by physician specialty, vertical integration of physician practices with hospitals or health systems was associated with lower income for nonsurgical specialists, no difference in income for primary care physicians, and slightly higher income for surgical specialists. Although vertical integration of physician practices is a rapidly growing trend, physicians might not directly benefit financially.

The Association between Hospital-Physician Vertical Integration and Outpatient Physician Prices Paid by Commercial Insurers: New Evidence.

This study assessed the relationship between hospital ownership of physician organizations (known as hospital-physician vertical integration) and facility fees billed to commercial insurers and physician service prices. Healthcare claims came from the IBM® MarketScan® Commercial Database (2012-2016, N = 30,716,800 office visit claims [CPT codes 99211-99215]), and hospital-physician vertical integration measures were from SK&A Office Based Physicians Database provided by IQVIA. Multi-variate, fixed-effect models were used to regress prices on market-level hospital-physician vertical integration; models included geographic market and year fixed effects, claim-level variables, and time-varying market-level variables. Analyses did not find that market-level hospital-physician vertical integration was associated with the billing of facility fees for office visits. However, vertical integration was associated with office visit physician prices for some specialties. A 10-percentage-point increase in vertical integration was associated with a 1.0% price increase for primary care, a 0.6% increase for orthopedics, and a 0.5% increase for cardiology; no such association was found for obstetrics/gynecology or oncology. When comparing metropolitan statistical areas (MSAs) in the bottom quartile of changes in vertical integration from 2012 to 2016 to MSAs in the top quartile, we found the following relative price increases based on predicted values for claims in the top quartile: $1.64 (1.9% of mean 2012 predicted price) for primary care to $2.30 (3.1%) for orthopedics to $3.13 (3.4%) for cardiology. Differences in predicted price accounted for an estimated $45.8 million in additional expenditure on primary care office visits in the top quartile of MSAs in 2016. In summary, market-level hospital-physician vertical integration was positively associated with physician prices for select specialties, but was not associated with changes in the use of facility-fee billing. More evidence on the quality effects of hospital-physician vertical integration is needed, as price increases that are not accompanied by measurable quality improvements should be part of any regulatory review.

States' Merger Review Authority Is Associated With States Challenging Hospital Mergers, But Prices Continue To Increase.

States can challenge proposed hospital mergers by using antitrust laws to prevent anticompetitive harms. This observational study examined additional state laws-principally charitable trust, nonprofit corporation, health and safety, and certificate-of-need laws-that can serve as complements and substitutes for antitrust laws by empowering states to be notified of, review, and challenge proposed hospital mergers through administrative processes. During the period 2010-19, 862 hospital mergers were proposed, but only forty-two (4.9 percent) were challenged by states, including thirty-five by states without federal involvement, of which twenty-five (71.4 percent) originated in the eight states with the most robust merger review authority. The twenty-five challenges resulted in two mergers being blocked; three being abandoned; and twenty being approved with conditions, including seven with competitive-impact conditions. Hospital market concentration and prices increased at similar rates in these eight states versus other states, potentially because most challenges allowed mergers to proceed with conditions that did not adequately address competitive concerns. Although these findings do not reveal an optimal state framework, elements of advanced state merger review authority may have the potential to improve poorly functioning hospital markets.

Practice composition and sex differences in physician income: observational study.

OBJECTIVE: To assess whether differences in income between male and female physicians vary according to the sex composition of physician practices. DESIGN: Retrospective observational study. SETTING: US national survey of physician salaries, 2014-18. PARTICIPANTS: 18 802 physicians from 9848 group practices (categorized according to proportion of male physicians ≤50%, >50-75%, >75-90%, and >90%). MAIN OUTCOME MEASURES: Sex differences in physician income in relation to the sex composition of physician practices after multivariable adjustment for physician specialty, years of experience, hours worked, measures of clinical workload, practice type, and geography. RESULTS: Among 11 490 non-surgical specialists, the absolute adjusted sex difference in annual income (men versus women) was $36 604 (£29 663; €32 621) (95% confidence interval $24 903 to $48 306; 11.7% relative difference) for practices with 50% or less of male physicians compared with $91 669 ($56 587 to $126 571; 19.9% relative difference) for practices with at least 90% of male physicians (P=0.03 for difference). Similar findings were observed among surgical specialists (n=3483), with absolute adjusted sex difference in annual income of $46 503 ($42 198 to $135 205; 10.2% relative difference) for practices with 50% or less of male physicians compared with $149 460 ($86 040 to $212 880; 26.9% relative difference) for practices with at least 90% of male physicians (P=0.06 for difference). Among primary care physicians (n=3829), sex differences in income were not related to the proportion of male physicians in a practice. CONCLUSIONS: Among both non-surgical and surgical specialists, sex differences in income were largest in practices with the highest proportion of male physicians, even after detailed adjustment for factors that might explain sex differences in income.

Stem-loop binding protein expressed in growing oocytes is required for accumulation of mRNAs encoding histones H3 and H4 and for early embryonic development in the mouse.

Growing oocytes accumulate mRNAs and proteins that support early embryogenesis. Among the most abundant of these maternal factors are the histones. Histone mRNA accumulation and translation are mainly restricted to S-phase in somatic cells, and the mechanism by which oocytes produce histones is unknown. In somatic cells, replication-dependent histone synthesis requires the stem-loop binding protein (SLBP). SLBP is expressed during S-phase, binds to the 3'-untranslated region of non-polyadenylated transcripts encoding the histones, and is required for their stabilization and translation. SLBP is expressed in oocytes of several species, suggesting a role in histone synthesis. To test this, we generated transgenic mice whose oocytes lack SLBP. mRNAs encoding histones H3 and H4 failed to accumulate in these oocytes. Unexpectedly, mRNAs encoding H2A and H2B were little affected. Embryos derived from SLBP-depleted oocytes reached the 2-cell stage, but most then became arrested. Histones H3 and H4, but not H2A or H2B, were substantially reduced in these embryos. The embryos also expressed high levels of gamma H2A.X. Injection of histones into SLBP-depleted embryos rescued them from developmental arrest. Thus, SLBP is an essential component of the mechanism by which growing oocytes of the mouse accumulate the histones that support early embryonic development.

Projecting shortages and surpluses of doctors and nurses in the OECD: what looms ahead.

There is little debate that the health workforce is a key component of the health care system. Since the training of doctors and nurses takes several years, and the building of new schools even longer, projections are needed to allow for the development of health workforce policies. Our work develops a projection model for the demand of doctors and nurses by Organisation for Economic Co-operation and Development (OECD) countries in the year 2030. The model is based on a country's demand for health services, which includes the following factors: per capita income, out-of-pocket health expenditures and the ageing of its population. The supply of doctors and nurses is projected using country-specific autoregressive integrated moving average models. Our work shows how dramatic imbalances in the number of doctors and nurses will be in OECD countries should current trends continue. For each country in the OECD with sufficient data, we report its demand, supply and shortage or surplus of doctors and nurses for 2030. We project a shortage of nearly 400,000 doctors across 32 OECD countries and shortage of nearly 2.5 million nurses across 23 OECD countries in 2030. We discuss the results and suggest policies that address the shortages.

Consolidation Trends In California's Health Care System: Impacts On ACA Premiums And Outpatient Visit Prices.

California has heavily concentrated hospital, physician, and health insurance markets, but their current structure and functioning is not well understood. We assessed consolidation trends and performed an analysis of "hot spots"-markets that potentially warrant concern and scrutiny by regulators in terms of both horizontal concentration (such as hospital-hospital mergers) and vertical integration (hospitals' acquisition of physician practices). In 2016, seven counties were high on all six measures used in our hot-spot analysis (four horizontal concentration and two vertical integration measures), and five counties were high on five. The percentage of physicians in practices owned by a hospital increased from about 25 percent in 2010 to more than 40 percent in 2016. The estimated impact of the increase in vertical integration from 2013 to 2016 in highly concentrated hospital markets was found to be associated with a 12 percent increase in Marketplace premiums. For physician outpatient services, the increase in vertical integration was also associated with a 9 percent increase in specialist prices and a 5 percent increase in primary care prices. Legislative proposals, actions by the state's attorney general, and other regulatory changes are suggested.

microRNA profile datasets of murine macrophages infected with different strains of Leptospira spp.

MicroRNAs play an important role in the regulation of immune responses. The influence of epigenetic mechanisms, particularly RNA-mediated post-transcriptional regulation of host immune responses has been proven vital following infections by different pathogens, and bacteria can modulated host miRNAs. Global miRNA expression analysis from macrophages infected in vitro with different strains of Leptospira spp was performed using miRNA 4.1 microarray strips. Leptospirosis is a bacterial zoonosis of global importance, responsible for significant morbidity and mortality worldwide. Despite considerable advances, much is yet to be discovered about disease pathogenicity, particularly in regards to host-pathogen interactions. We present here a high-quality dataset examining the microtranscriptome of murine macrophages J774A.1 following 8h of infection with virulent, attenuated and saprophyte strains of Leptospira. Metadata files were submitted to the Gene Expression Omnibus (GEO) repository.

Placental growth throughout the last two thirds of pregnancy in sheep: vascular development and angiogenic factor expression.

Morphometric methodologies were developed and applied to investigate the patterns of vascular development in maternal (caruncular; CAR) and fetal (cotyledonary; COT) sheep placentas throughout the last two thirds of gestation. We also examined the expression levels of the major angiogenic factors and their receptors in CAR and COT sheep placentas. Although the vascularity of the CAR tissues increased continuously from Day 50 through Day 140 of pregnancy, those of the COT tissues increased at about twice the instantaneous rate (i.e., the proportionate increase/day) of the CAR. For CAR, vascularity increased 2-fold from Day 50 through Day 140 via relatively small increases in capillary number and 2- to 3-fold increases in capillary diameter. For COT, the increased vascularity resulted from a 12-fold increase in capillary number associated with a concomitant 2-fold decrease in capillary diameter. This large increase in fetal placental capillary number, which was due to increased branching, resulted in 6-fold increases in total capillary cross-sectional area and total capillary surface, per unit of COT tissue. Different patterns of expression of the mRNAs for angiogenic factors and their receptors were observed for CAR and COT. The dilation-like angiogenesis of CAR was correlated with the expression of vascular endothelial growth factor receptor-1 (FLT1), angiopoietin-2 (ANGPT2), and soluble guanylate cyclase (GUCY1B3) mRNAs. The branching-like angiogenesis of COT was correlated with the expression of vascular endothelial growth factor (VEGF), FLT1, angiopoietin-1 (ANGPT1), ANGPT2, and FGF2 mRNAs. Monitoring the expression of angiogenic factors and correlating the levels with quantitative measures of vascularity enable one to model angiogenesis in a spatiotemporal fashion.

Countervailing incentives in value-based payment.

Payment reform has been at the forefront of the movement toward higher-value care in the U.S. health care system. A common belief is that volume-based incentives embedded in fee-for-service need to be replaced with value-based payments. While this belief is well-intended, value-based payment also contains perverse incentives. In particular, behavioral economists have identified several features of individual decision making that reverse some of the typical recommendations for inducing desirable behavior through financial incentives. This paper discusses the countervailing incentives associated with four behavioral economic concepts: loss aversion, relative social ranking, inertia or status quo bias, and extrinsic vs. intrinsic motivation.

Insurer Market Power Lowers Prices In Numerous Concentrated Provider Markets.

Using prices of hospital admissions and visits to five types of physicians, we analyzed how provider and insurer market concentration-as measured by the Herfindahl-Hirschman Index (HHI)-interact and are correlated with prices. We found evidence that in the range of the Department of Justice's and Federal Trade Commission's definition of a moderately concentrated market (HHI of 1,500-2,500), insurers have the bargaining power to reduce provider prices in highly concentrated provider markets. In particular, hospital admission prices were 5 percent lower and cardiologist, radiologist, and hematologist/oncologist visit prices were 4 percent, 7 percent, and 19 percent lower, respectively, in markets with high provider concentration and insurer HHI above 2,000, compared to such markets with insurer HHI below 2,000. We did not find evidence that high insurer concentration reduced visit prices for primary care physicians or orthopedists, however. The policy dilemma that arises from our findings is that there are no insurer market mechanisms that will pass a portion of these price reductions on to consumers in the form of lower premiums. Large purchasers of health insurance such as state and federal governments, as well as the use of regulatory approaches, could provide a solution.

Consumers Buy Lower-Cost Plans On Covered California, Suggesting Exposure To Premium Increases Is Less Than Commonly Reported.

With the notable exception of California, states have not made enrollment data for their Affordable Care Act (ACA) Marketplace plans publicly available. Researchers thus have tracked premium trends by calculating changes in the average price for plans offered (a straight average across plans) rather than for plans purchased (a weighted average). Using publicly available enrollment data for Covered California, we found that the average purchased price for all plans was 11.6 percent less than the average offered price in 2014, 13.2 percent less in 2015, and 15.2 percent less in 2016. Premium growth measured by plans purchased was roughly 2 percentage points less than when measured by plans offered in 2014-15 and 2015-16. We observed shifts in consumer choices toward less costly plans, both between and within tiers, and we estimate that a $100 increase in a plan's net annual premium reduces its probability of selection. These findings suggest that the Marketplaces are helping consumers moderate premium cost growth.