Effects of Agricultural Research and Farm Subsidy Policies on Human Nutrition and Obesity Agricultural Issues Center Julian Alston Daniel Sumner Stephen Vosti Center For Natural Resources Policy Analysis, UC Davis November 2005 TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Presentation Outline • Obesity in the U.S. – Trends, Costs and Presumed Causes • One „Smoking Gun‟ – HFCS and „Related‟ Ag Policies • A Broader Look at Agricultural Policy – Farm Subsidies and R&D • Commodity Prices • Food Prices • Policy Instrument „Test‟ • Preliminary Conclusions and Implications for Research and Policy TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Children with BMI values at or above the 95th percentile of the sex-specific BMI growth charts are categorized as overweight. TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Obesity Trends* Among U.S. Adults BRFSS, 1991, 1996, 2003 (*BMI 30, or about 30 lbs overweight for 5’4” person) 1991 1996 2003 No Data <10% 10%-14% 15%-19% Source: Behavioral Risk Factor Surveillance System, CDC. 20%-24% 25% TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Economic Costs • Direct – Increased health care costs • $78.5 billion in the U.S. in 1998 • $7.8 billion in California alone, 1998-2000 • Indirect – Morbidity costs • Lost productivity • Absenteeism – Mortality costs • Over 300,000 death per year attributable to obesity • Obese individuals have a 50 to 100% increased risk of premature death from all causes TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Key Issues • Why Is Obesity on the Rise? – Long-Term and Worsening Energy Imbalance • Energy Intake > Energy Expenditure • Drivers of This Imbalance – Types and sources of food – Food portions – Energy expenditure patterns • What Role of Agriculture and Agricultural Policy? – Getting us to this point? – Course correction? TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Food Types and Sources Are Changing • Eating More Energy-Dense Foods – Potato chips (23kJ/g), donuts (18 kJ/g), cheese (17 kJ/g), low-fat milk (1.6 kJ/g), raw vegetables and fruits (0.4-2.0 kJ/g) • Snacks Versus Meals – Snacks – increasing proportion of caloric intake – Meals – decreasing proportion of caloric intake • Meals Eaten Away-from-Home – 1977: 16% of food, 38% of all food expenditures – 1997: 29% of food, 49% of all food expenditures TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Food Portions On The Rise • McDonalds French Fries – – – – 1950: one size (210 cal.) 1970: small (210 cal.) and large (320 cal.) 1990: small (210 cal.), large (450 cal.) and Super 450 cal.) 2000: small (210 cal.), medium (450 cal.), large (540 cal.) and super (610 cal.) • Coke – – – – – – – Original: 6.75 oz. (75 cal.) Kids: 10 oz. (120 cal.) Small: 12 oz. (150 cal.) Medium: 18 oz. (230 cal.) Large: 24 oz. (300 cal.) King: 36 oz. (450 cal.) Extreme Gulp: 52 oz. (650 cal.) TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Is Agricultural Policy (Partially) Responsible? • “[Our] cheap-food farm policy comes at a high price: . . . farmers in the United States have managed to produce 500 additional calories per person every day; each of us is, heroically, managing to pack away 200 of those extra calories per day.” (Pollan 2003) • “Commodity prices . . . are so low that restaurants have been able to double serving sizes without doubling prices.” (Davis 2003) • “Why healthier foods are slipping out of reach of large segments of the US population is a question with many policy and political implications.” (Drewnowski and Barratt-Fornell, 2004) Alston, Sumner, Vosti UCD/AIC/CNRPA TP Tomich One „Smoking Gun‟ Avg. Kcalories/person/day Trends in Consumption of Corn Sweeteners 250 200 150 100 50 0 1965 1970 1975 1980 1985 1990 1995 2000 2005 Year Corn sweeteners http://www.ers.usda.gov/data/foodconsumption/FoodGuideIndex.htm#calories TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA The Suspected Culprit – Corn Policy Producer Support Estimate -- Corn Corn Prices 12,000 USD/ton 8,000 6,000 4,000 2,000 III. Producer Support Estimate (PSE) 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 19 86 19 87 19 88 19 89 19 90 19 91 19 92 19 93 19 94 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 04 20 03 20 02 20 01 20 00 19 99 19 98 19 97 19 96 19 95 19 94 19 93 19 92 19 91 19 90 19 89 19 88 1. Based on unlimited output V. Consumption price (at farm gate) C. Payments based on area planted D. Payments based on historical entitlements E. Payments based on input use E. Payments based on input use F. Payments based on input constraints G. Payments based on overall farming income VII. Reference price (at farm gate) Consumer Support Estimate (CSE) -- Corn 4,000 3,000 2,500 2,000 1,500 1,000 500 XIII. Consumer Support Estimate (CSE) 20 04 20 03 20 02 20 01 20 00 19 99 19 98 19 97 19 96 19 95 19 93 19 92 19 91 19 90 19 89 19 88 19 87 0 19 86 Millions USD (current) 3,500 19 94 -2,000 19 87 0 19 86 Millions USD (current) 10,000 TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA The More Complete Story Avg. Kcalories/person/day Trends in Consumption of Selected Sweeteners 600 500 400 300 200 100 0 1965 1970 1975 1980 Refined cane and beet sugar 1985 1990 Year Corn sweeteners http://www.ers.usda.gov/data/foodconsumption/FoodGuideIndex.htm#calories 1995 2000 2005 All Added sugars TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA White Sugar Policy – What Role? Sugar Prices in the USA -- 1986-2004 35 30 25 20 15 10 5 0 19 86 19 87 19 88 19 89 19 90 19 91 19 92 19 93 19 94 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 Years VIII.1 Domestic reference price (New York Spot) Producer Support Estimate -- Sugar $1,200 $1,000 $800 $600 $400 $200 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 $0 1986 VII.1 World reference price Millions USD (1977) cents/pound (current) 40 PSE TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA The Australia Story: Sugar Policy Sugar Prices -- Australia 300 200 150 100 50 0 19 86 19 87 19 88 19 89 19 90 19 91 19 92 19 93 19 94 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 AUD/ton (current) 250 V. Consumption price (at farm gate) VII. Reference price (at farm gate) TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA The Australia Story: Obesity Trends TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA The Much More Complete Story Avg. Kcalories/person/day Calories from Differrent Food Groups 700 600 500 400 300 200 100 0 1965 1970 1975 Meat, eggs, and nuts Vegetables Added sugars 1980 1985 Year 1990 Dairy Flour and cereal products http://www.ers.usda.gov/data/foodconsumption/FoodGuideIndex.htm#calories 1995 2000 2005 Fruit Added fats TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Types and Magnitudes of Agricultural Policies USDA Program Expenditure in 2004 Percent of Total billions of dollars percent Food, Nutrition, and Consumer Services 45.4 40.2 Farm Service Agency (mainly farm commodity programs) 27.4 24.3 Rural Development 15.5 13.7 Natural Resources and Environment 8.4 7.4 Foreign Agricultural Service 6.4 5.7 Risk Management (mainly crop insurance) 4.1 3.6 Research, Education and Economics (mainly ag. R&D) 2.5 2.2 Marketing and Regulatory Programs 1.8 1.6 Other 1.4 1.2 112.9 100.0 TOTAL TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Links Between Selected Agricultural Policies and Human Nutrition Agricultural R&D Agricultural Commodity Programs Farm Production Costs Commodity Prices Farm Income Food Industry Food Prices Food Intake Disposable Income Available Time Genetic Factors Information & Sociocultural Factors Activity Levels Nutritional Status TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Support to Agriculture General Services Suppost Estimate Producer Support Estimates 40,000 Millions of USD (current) 60,000 40,000 30,000 20,000 10,000 30,000 25,000 20,000 15,000 10,000 5,000 A. Market price support M. Marketing and promotion B. Payments based on output C. Payments based on area planted/animal numbers D. Payments based on historical entitlements F. Payments based on input constraints E. Payments based on input use G. Payments based on overall farming income 04 02 01 03 20 20 20 00 20 99 20 97 98 19 N. Public stockholding Transers from Taxpayers to Consumers -- All Commodities 30,000 40,000 25,000 Millions USD (current) 30,000 20,000 10,000 04 03 02 01 00 99 98 97 96 95 94 93 20,000 15,000 10,000 5,000 20 20 20 20 20 19 19 19 19 19 19 92 19 90 91 19 19 88 87 89 19 19 19 19 86 0 19 Millions of USD (current) I. Research and development O. Miscellaneous Consumer Support Estimates -10,000 19 96 IV. General Services Support Estimate (GSSE) III.1 Producer Support Estimate (PSE) 19 94 95 19 19 92 93 19 19 90 89 88 91 19 19 19 19 19 86 19 19 86 19 87 19 88 19 89 19 90 19 91 19 92 19 93 19 94 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 87 0 0 19 Millions of USD (current) 50,000 35,000 0 -20,000 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 -30,000 R. Transfers to consumers from taxpayers Food stamp program 0.36 * 12-3505-0-1-605 Nutrition Assistance for Puerto Rico 12-3550-0-1-605 V.1 Consumer Support Estimate (CSE) Q. Other transfers from consumers (-) S. Excess feed cost P. Transfers to producers from consumers (-) R. Transfers to consumers from taxpayers State Child Nutrition Program 12-3539-0-1-605 WIC nutrition programs 12-3510-0-1-605 TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Trends in Agricultural R&D Spending Total Federal and State Spending on Ag. R&D (1925-1997) 3500 3000 2000 1500 1000 500 1997 Year Total Private Sector Spending on Ag R&D (1960-1992) Total Ag. R&D Spending 4000 3500 3000 2000 1500 1000 500 1992 1990 1988 1986 1984 1982 1980 1978 1976 1974 1972 1970 1968 1966 1962 0 1960 mil. $ 2500 1964 1993 1989 1985 1981 1977 1973 1969 1965 1961 1957 1953 1949 1945 1941 1937 1933 1929 0 1925 mil. $ 2500 Year Private Ag R&D Spending TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Trends in Aggregate Productivity Measures Index of Land Productivity (1977=100) 140 Index of Labor Productivity (1977=100) 160 120 140 100 120 80 100 60 80 40 60 40 20 20 1982 1978 1974 1970 1966 1962 1958 1954 1950 1946 1942 1938 1934 1930 1926 1922 1918 1910 Year 1914 0 1990 1985 1980 1975 1970 1965 1960 1955 1950 1945 Year Land Productivity Labor Productivity Total Factor Productivity Index (1948=100) 300 250 200 150 100 50 Year TFP 1996 1993 1990 1987 1984 1981 1978 1975 1972 1969 1966 1963 1960 1957 1954 1951 0 1948 1940 1935 1930 1925 1920 1915 1910 0 TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Trends in Crop/Product Productivity Average Yield of Corn 1900-1997 160 140 100 80 60 40 20 1996 Year Avg. Corn Yield Milk Production per Cow 1929-1996 18000 16000 12000 10000 8000 6000 4000 2000 1993 1989 1985 1981 1977 1973 1969 1965 1961 1957 1953 1949 1941 1937 1933 0 1929 lbs./cow 14000 1945 1990 1984 1978 1972 1966 1960 1954 1948 1942 1936 1930 1924 1918 1912 1906 0 1900 bush./acre 120 Year Milk per Cow TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Trends in Prices Received By Farmers Prices received Deflated w ith prices paid (Com m odities, services, interest, taxes, w ages) (1977=100) Deflated Prices Received for Selected Grains (1977=100) 180 250 160 140 200 120 150 100 80 100 60 50 40 20 2002 1999 1996 1993 1990 1987 1984 1981 1978 1975 1972 1969 1966 1960 2002 1999 1996 1993 1990 1987 Years Rice (PP) All Farm Products Wheat (PP) Corn for Grain Deflated Prices Received for Selected Fruits (1977=100) 250 200 150 100 50 2002 1999 1996 1993 1990 1987 1984 1981 1978 1975 1972 1969 1963 1960 0 1966 1984 1981 1978 1975 1972 1969 1963 1960 1966 All Crops Year Livestock & Products 1963 0 0 Year Apples Oranges Straw berries Table Grapes TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Prices Paid By Consumers – Basic Stuff Consumer Prices for Ground Beef Deflated by CPI (food at home) Consum er Prices for Eggs Deflated by CPI (food at hom e) 2.50 2.00 1.00 0.80 $/lb. 0.60 0.40 1.50 1.00 2004 2000 1996 1992 1988 0.00 Year 1984 0.50 2004 2000 1996 1992 1988 1984 1980 0.20 0.00 1980 $/doz. 1.40 1.20 Year Eggs, Grade A Large Ground Chuck, USDA Choice Cons.Food_Prices!$N$7, 100% Beef Consumer Prices for White Sugar Deflated by CPI (food at home) 1.00 0.70 0.90 0.60 0.80 0.50 $/lb. 0.70 0.40 0.60 0.30 0.50 0.20 0.40 Chicken, w hole, fresh 2001 1994 1987 2004 2000 1996 1988 1984 1992 Year 1980 0.10 0.30 1980 $/lb. Consumer Prices for Chicken deflated by CPI (food at home) Year Sugar, w hite, all sizes TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Prices Paid By Consumers – Fruits and Vegetables Consumer Prices for Oranges Deflated by CPI (food at home) Consumer Prices for Broccoli Deflated by CPI (food at home) 1.20 0.90 0.80 1.00 0.70 0.60 $/lb. $/lb. 0.80 0.60 0.50 0.40 0.30 0.40 0.20 0.10 0.20 2004 2000 1996 1992 1988 2004 2003 2002 2001 2000 1999 1998 1997 1996 0.00 1984 1980 0.00 Year Year Broccoli Oranges, Navel Oranges, Valencia Consumer Prices for Strawberries Deflated by CPI (food at home) Consumer Prices for Potatoes Deflated by CPI (food at home) 2.50 0.35 2.00 0.30 $/12 oz. 0.20 0.15 1.50 1.00 0.10 0.50 0.05 Year Potatoes, w hite Year Straw berries, Dry pint 2004 2000 1996 1992 1988 1984 0.00 1980 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 0.00 1986 $/lb. 0.25 TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Getting the Price Story Right: Strawberries Year Jan Feb Mar 1980 Apr May Jun 0.653 0.608 0.66 Jul 1981 0.886 0.69 0.637 0.696 0.77 1982 1.016 0.914 0.73 0.778 0.775 0.728 0.708 0.752 0.863 1983 Aug 1984 0.912 0.663 0.648 0.78 0.827 1985 1.016 0.809 0.646 0.774 0.913 1986 0.637 0.797 0.718 0.84 0.899 1.081 0.937 0.824 0.955 1.071 1.029 1987 Sep Oct Nov Dec 0.943 1988 1.181 0.693 0.919 0.937 1.059 0.971 1.216 1989 1.218 0.966 0.831 1.055 1.117 0.986 1.087 1990 1.638 1.338 1.109 0.781 0.987 0.965 1.081 1.21 1991 1.467 1.268 1.112 0.976 0.924 0.948 0.961 1.014 1.035 1992 1.43 1.173 0.96 0.831 1.048 0.988 1.185 1.473 1.19 1993 1.467 1.26 0.908 0.874 1.066 1.013 1.069 1.151 1.261 1994 1.318 1.262 0.91 0.983 1.047 1.085 1.108 1.209 1.286 1995 1.926 1.34 1.001 1.14 1.18 1.209 1.398 1.355 1.316 1.505 1.236 1.082 0.957 1.226 1.247 1.164 1.42 1.409 1.514 1.317 1.179 1.073 1.213 1.383 1.375 1.488 2.08 1.751 1.613 1.386 1.413 1.346 1.454 1.469 1.779 2.102 1.96 1.751 1.419 1.49 1.375 1.557 1.679 1.664 1.935 1.825 1.45 1.218 1.187 1.246 1.263 1.416 1.619 2.14 2.01 1.737 1.482 1.465 1.486 1.628 1.916 1.996 2.137 2.137 1.941 1.551 1.527 1.552 1.545 1.695 1.873 1.884 2.224 2.153 1.871 1.762 1.678 1.568 1.776 1.84 1.986 2.246 2.41 2.332 2.124 1.661 1.672 1.847 1.629 1.817 1.843 2.6 3.185 1996 1.692 1997 1998 2.135 1999 2000 2.167 2001 2002 2.498 2003 2004 2.481 1.654 1.948 2.526 TP Tomich 3.602 Alston, Sumner, Vosti UCD/AIC/CNRPA A Closer Look at Strawberry Prices Consumer Prices for Strawberries Deflated by CPI (food at home) June Strawberry Prices (BLS data) 2.50 Price $ per dry pint (12oz) - 1.50 1.00 0.50 1 0.8 0.6 0.4 y = -0.0089x + 18.289 R2 = 0.5356 0.2 0 1975 1980 2004 2000 1996 1992 1988 1984 0.00 1985 1990 1995 2000 2005 2010 Year Year Straw berries, Dry pint Feb Strawberry Prices (BLS data) Price $ per dry pint (12oz) - 1980 $/12 oz. 2.00 1.2 1 0.8 0.6 0.4 y = -0.0003x + 1.4305 R2 = 0.0003 0.2 0 1988 1990 1992 1994 1996 1998 Year 2000 2002 2004 2006 TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Consumer Prices for Foods White Bread: 0.0 Rice: -.031 Pasta: -.008 Lettuce: -.004 Tomatoes: +.003 Carrots: -.003 Potatoes: 0.0 Bananas: -.004 Apples: -.006 Oranges: 0.0 Grapefruit: -.002 White Sugar: -.008 Butter: -.023 Milk: -.011 Cheese: -.033 Statistics report linear trends in real prices over 1980-2003: source; http://data.bls.gov/ Turkey: -.021 Chicken: -.009 Eggs: -.015 Beef: -.031 TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Food Prices in Terms of the Wages • Tomatoes (3 lbs.) (18% of the historical price today) – 1919: 101 minutes – 1997: 18 minutes • An Orange (13% of the historical price today) – 1919: 68 minutes – 1997: 9 minutes • 3-Pound Chicken (9% of the historical price today) – 1919: 2hours 37 minutes – 1997: 14 minutes • Dozen Eggs (6% of the historical price today) – 1919: 80 minutes – 1997: 5 minutes • Hamburger (33% of the historical price today) – 1940: 27 minutes of work – 1997: 9 minutes of work • Pizza (88% of the historical price today) – 1958: 57 minutes – 1997: 50 minutes TP Tomich Source: Dallas Fed Alston, Sumner, Vosti UCD/AIC/CNRPA „Disconnect‟ Between Commodity & Food Prices 200.0 180.0 160.0 140.0 120.0 100.0 80.0 60.0 40.0 20.0 0.0 19 29 19 54 19 57 19 60 19 63 19 66 19 69 19 72 19 75 19 78 19 81 19 84 19 87 19 90 19 93 19 96 19 99 20 02 Proportion of Retail Store Prices Divergence Between Retaurant and Shippers' Prices TP Tomich Restaurant prices Retail store prices Manufacturers' and shippers' prices Alston, Sumner, Vosti UCD/AIC/CNRPA Costs of Producing Fast Foods 03 20 01 20 99 19 97 19 95 93 91 89 87 85 Year Year Producer Price for Beef (1977 = 1) 19 2005 19 2000 19 1995 19 1990 19 1985 19 Ye 1980 83 0.10 0.00 ar 0.2 0.20 19 0.4 0.30 81 1 0.8 0.6 0.40 19 Cost (1982 US$) 1.2 Producer Price for Milk (1977 = 1) Producer Price for Wheat (1977 = 1) Hamburger (1/4 lb.) Hamburger Bun (2 Ounces) Cheese (8 Grams) Pecent of Costs and Expenses McDonalds Corporation 100% % Selling and administrative expenses of costs and expenses % Occupancy and other operating expenses of costs and expenses % Payroll of costs and expenses - 90% Percent of Cost Farmer Price - 1.4 0 1975 Costs to Consumer for Components MacDonalds Quarter Pounder with Cheese - Farmer Prices for the Components of a McDonalds Quarter Pounder 80% 70% 60% 50% 40% 30% 20% % food and paper of costs and expenses 10% 0% 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 Year http://www.mcdonalds.com/corp/invest/pub.html TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Policy Instrument „Test‟ • Size of the Externality – Social costs associated with obesity • Size of Behavioral Response – Price elasticities tend to be very low (USA) • • • • Implementation Costs Lags in Intended Effects Unintended Effects Alternative Policy Instruments Elasticity estimates from: http://www.ers.usda.gov/Data/InternationalFoodDemand/ TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Preliminary Conclusions and Policy Implications • Agricultural Policy Commodity Prices – Commodity Support Programs • Effects on farmer income are large; Effects on commodity prices are small, varied and difficult to predict – Publicly Sponsored Agricultural Research • Chiefly responsible for past yield increases and price declines • Commodity Prices Food Prices Caloric Intake – Increasing „disconnect‟ between commodity prices and food prices – Role of food industry needs to be better understood and exploited • Entry points for changes in food preparation technologies and portion sizes • Managing food consumption via macro-management of commodity prices is probably a bad strategy – Is cheap food a bad thing? – Can reductions in agricultural R&D reduce obesity? • Micro-Management of Food Prices Might Not Be Wise – Price responses are generally low • Agricultural Policy for Dealing with Obesity – Increased yields, and improved quality and availability of fruits/vegetables • Large role for private sector • Difficult to Defend the „Increasingly Out of Reach‟ Hypothesis TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Next Steps • ASSA Paper (Joint Presentation with IFPRI/FCND) – Implications for developing countries of research results to date • USDA Small Grant – Effects of agricultural policies on low-income consumers in the USA • USDA Large Grant (pending) – Joint with Iowa State University – Agricultural policies, sweetener subsector, WIC • Research, training, outreach, curriculum development • Dual-Constraint Model – Combined effects of income and time constraints on consumption patterns of low-income groups TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA Muito Obrigado! TP Tomich Alston, Sumner, Vosti UCD/AIC/CNRPA