粮食产业是我国国民经济的基础产业，粮食安全直接影响其他产业的发展。近年来，国际粮食安全形势严峻，全球正面临着30年来最为严重的粮食危机。中国是人口大国，粮食安全问题受到了前所未有的关注，由于我国粮食价格出现了频繁且剧烈的波动，粮食供需矛盾日益凸显，导致生活成本不断提高，进而影响不同层次主体的福利变化。第一，采用定性分析法考察我国粮食生产现状及主产区、产销平衡区和主销区粮食产量、粮食播种面积和粮食价格的变动趋势。在分区基础上，建立了粮食供给和需求模型，估计三大区域粮食供给价格弹性、需求的收入弹性和价格需求弹性，在对三个产区粮食供给和需求弹性进行分析的基础上，借鉴Minot和Goletti（2000）提出的农作物价格变动的福利效应模型，对我国三大区域粮食价格波动中的福利效应进行测算和分解。第二，对粮食价格波动中微观主体农户福利效应的变动进行量化分析，考察城镇不同收入水平居民粮食价格波动的福利变化，并在此基础上，对比分析粮食价格波动对农村居民与城镇居民的不同影响及其机理，并提出有针对性的政策建议。第三，考察农户对粮价波动的行为响应，探讨粮食价格波动—农户福利变化—农户种粮行为这一链条的作用机制，测算农户短期和长期对价格、成本、单产纯收益等因素变化刺激反应的灵敏程度，在此基础上对比分析价格与收益因素对粮食作物的影响，分析粮价波动对农户种粮积极性的影响。第四，在理论探索和实证分析基础上，考察粮食价格波动原因，分别探讨封闭与开放条件下技术进步导致粮食价格波动的内在机理；加入世界贸易组织后，随着农产品贸易政策的不断放开，我国粮食进出口量大大增加，本书分析关税变动对政府、消费者和生产者等不同主体福利变动的影响。最后，对政策调控的有效性进行分析，考察政府调控粮食价格波动的手段（或选择组合）及各种调控手段的有效性；设计不同的政策模拟情景，考察区域补贴政策、粮食直补、财政投入政策等对区域政府粮食行为和农户生产行为及其粮食供给的影响，探讨政府调控政策的激励强度和调控效果。在此基础上，提出社会福利最大化目标下调控政策优化的途径和方案。

The grain industry is the basic industry of China's national economy, and food security directly affects the development of other industries. In recent years, the international food security situation has been grim, and the world is facing the most serious food crisis in 30 years. China is a populous country, food security has received unprecedented attention, due to frequent and violent fluctuations in China's food prices, the contradiction between food supply and demand has become increasingly prominent, resulting in an increasing cost of living, which in turn affects the welfare changes of different levels of subjects. First, the qualitative analysis method is used to investigate the current situation of grain production in China and the change trend of grain output, grain sown area and grain price in the main producing areas, production and marketing balance areas and main sales areas. On the basis of zoning, a food supply and demand model is established to estimate the price elasticity, income elasticity and price demand elasticity of food supply in the three major regions, and on the basis of the analysis of the food supply and demand elasticity of the three producing areas, and drawing on the welfare effect model of crop price change proposed by Minot and Goletti (2000), the welfare effect in the fluctuation of food prices in the three major regions of China is measured and decomposed. Second, this paper quantifies the changes in the welfare effect of micro-main farmers in food price fluctuations, examines the welfare changes of food price fluctuations of residents with different income levels in cities and towns, and on this basis, compares and analyzes the different impacts and mechanisms of food price fluctuations on rural residents and urban residents, and puts forward targeted policy suggestions. Third, this paper examines the behavioral response of farmers to food price fluctuations, discusses the mechanism of the chain of food price fluctuations-changes in farmers' welfare-and farmers' grain planting behaviors, and measures the sensitivity of farmers to changes in price, cost, yield net income and other factors in the short and long term, and on this basis, the impact of price and income factors on food crops is compared and analyzed, and the impact of food price fluctuations on farmers' enthusiasm for growing grain is analyzed. Fourth, on the basis of theoretical exploration and empirical analysis, the causes of food price fluctuations are investigated, and the internal mechanisms of food price fluctuations caused by technological progress under closed and open conditions are discussed respectively. After joining the World Trade Organization, with the continuous liberalization of agricultural trade policies, China's grain import and export volume has greatly increased, and this book analyzes the impact of tariff changes on the welfare of different subjects such as governments, consumers and producers. Finally, the effectiveness of policy regulation is analyzed, and the effectiveness of government means (or combination of choices) and various regulatory means is examined. Different policy simulation scenarios were designed to examine the impact of regional subsidy policies, direct grain subsidies, and fiscal input policies on regional governments' food behavior, farmers' production behaviors and their food supply, and explore the incentive intensity and regulatory effect of government regulatory policies. On this basis, the ways and schemes for the optimization of regulatory policies under the goal of maximizing social welfare are proposed.（AI翻译）