Hege Medin

Upregulation of the lactate transporter monocarboxylate transporter 1 at the blood-brain barrier in a rat model of attention-deficit/hyperactivity...

The energy deficit hypothesis of attention-deficit/hyperactivity disorder (ADHD) suggests that low lactate production by brain astrocytes causes the symptoms of the disorder. Astrocytes are the main producers of lactate in the brain; however, skeletal muscles can produce the most lactate in the body. The lactate production by skeletal muscles increases with physical activity, as does the expression of the lactate transporter monocarboxylate transporter 1 (MCT1) at the blood-brain barrier (BBB). We hypothesise that children with ADHD, by being hyperactive, increase lactate production by skeletal muscles and transport it into the brain to compensate for low supply by astrocytes. The aim of this study was to explore whether the level of MCT1 is altered in the brain in an animal model of ADHD. The MCT1 expression was quantified on hippocampal brain sections from the best available rat model of ADHD, i.e., the spontaneously hypertensive rat (SHR) (n=12), and the relevant control, the Wistar Kyoto rat (WKY) (n=12), by the use of quantitative immunofluorescence laser scanning microscopy and postembedding immunogold electron microscopy. The results revealed significantly higher levels of hippocampal MCT1 immunoreactivity in SHR compared to WKY, particularly at the BBB. These results indicate that lactate flux through MCT1 between the body and the brain could be upregulated in children with ADHD. This study adds to previous research suggesting hyperactivity may be beneficial in ADHD; Children with ADHD possibly display a hyperactive behaviour in order to raise skeletal muscle lactate production, MCT1 expression and flux over the BBB to supply the brain with lactate.

Customs-brokers as facilitators in international trade

Recent studies suggest that firms can reduce fixed trade costs by hiring intermediaries like trading companies. I argue that customs brokers – a type of intermediary rarely studied in economics before – can play a similar role. Using panel data of Norwegian trade transactions, I show that such brokers are commonly used to clear goods through customs. I find indications of lower sunk costs as well as fixed trade costs for firms that hire such services. However, engaging brokers can be risky, and traders in high-risk products like food are more likely to self-declare. Results are similar for importing and exporting, indicating that customs brokers facilitate both modes of trade.

Market-specific Sunk Export Costs: The Impact of Learning and Spillovers

Firms may face sunk costs when entering an export market. Previous studies have focused on global or country-specific sunk export costs. This study analyses the importance of market-specific sunk export costs (defining ‘market’ as a product–country combination). We also study how market-specific export costs can be affected by various kinds of learning and spillover effects. We use firm-level panel data for Norwegian seafood exports distributed on products and countries. The results lend support to the hypothesis of market-specific sunk costs. We also find evidence of learning and spillover effects, particularly within the same product group.

TTIP and Norway: Impact and trade policy options

This study analyzes TTIP, its implications for Norway and Norway’s trade policy choices. TTIP will hardly be concluded under Obama's presidency, but the agreement could become a reality within a few years. TTIP aims at comprehensive cooperation in the regulatory area. In the short term there will be limited harmonization of standards but regulatory cooperation between different systems. In the long term, the goal is stronger cooperation in the regulatory area. TTIP will from what we know not lead to a lowering of European health regulations or a "race to the bottom". If TTIP is realized and Norway remains outside, the EEA Agreement will be little affected and the overall economic impact is moderate. If Norway joins TTIP, there will be a significant real income gain, with estimates ranging from 2236 to 6772 NOK per capita in the various scenarios. There is considerable variation across sectors. With Norway outside TTIP there will be a moderate negative impact for a majority of the sectors, especially some manufacturing sectors that face tougher competition in the EU and USA export markets. The oil industry will benefit from increased demand and higher prices. If Norway joins TTIP, a clear majority of industries will benefit; especially business services and a number of other service industries. The public sector gains from TTIP, mainly due to cheaper inputs. TTIP will contribute to the dismantling of import protection for Norwegian agriculture and without compensating measures, production and employment will be reduced. TTIP will still allow some import protection and this margin of maneuver, which depends on future negotiations, is important for the outcome. With a larger margin of manoeuvre and unchanged budgetarty support, most of Norway’s agriculture can be maintained. With less margin of manoeuvre, it will be more challenging. Norwegian accession to TTIP may occur in the form of a standard trade agreement in which Norway or EFTA are formally equal to the EU and the United States. Alternatively, Norway may participate in a European pillar as in today's "Open Skies" agreement on air traffic. If TTIP succeeds in establishing comprehensive regulatory cooperation, the latter solution is most likely. Such a solution implies that Norway will become more closely integrated with the European Union also in trade policy towards third countries. Norwegian entry into TTIP implies that we have to accept the established rules and negotiate bilaterally with the EU and the USA on market access. The negotiations with the USA will apply to all aspects of market access, while negotiations with the EU will apply only to areas in which the EEA agreement is not already deeper. The negotiations with the EU for TTIP entry will thus include, among other issues, tariffs for seafood and agriculture. As an alternative to membership in TTIP, Norway or EFTA may initiate a trade agreement with the USA. Such an agreement would likely be less extensive in the regulatory area. Such an agreement will also provide an economic gain for Norway, but less than accession to TTIP. For Norway as a whole, accession to TTIP creates a real income gain between 12.5 and 35 billion NOK according to various scenarios, while a free trade agreement with the United States results in a gain of about 7.4 billion NOK. TTIP also includes negotiations on so-called Investor-State Dispute Settlement (ISDS), whereby foreign-owned companies can sue a state if they are unfairly or inappropriately treated. Such rights also exist in national law but international tribunals have to some extent extended the interpretation of what is considered unfair. The European Union has proposed a solution in TTIP with a permanent court as well as rules that discipline the interpretation of the principles, and thus avoids that ISDS unduly interferes into the states’ "right to regulate". This and many other issues are analysed in this report and six background papers.

The reverse home market effect in exports: a cross-country study of the extensive margin of exports.

TTIP og Norge: Virkninger og handlingsvalg

Trade barriers or trade facilitators? On the heterogeneous impact of food standards in international trade

Darwinistisk seleksjon i en global økonomi

(This article is available in Norwegian only): Det siste tiåret har det blitt utviklet en ny retning innen samfunnsøkonomisk teori om internasjonal handel, såkalt ny-ny handelsteori. Teorien er inspirert av empiriske studier av handelsdata på bedriftsnivå og kan forklare en rekke særtrekk vi observerer ved eksportører, som for eksempel at de har langt større omsetning og er mer produktive enn ikke-eksportører. Teorien kan videre forklare hvordan slike forskjeller på mikronivå får konsekvenser for makroøkonomiske størrelser. Økt globalisering gjennom reduksjon i handelskostnader kan føre til økt gjennomsnittlig produktivitet innad i næringer gjennom darwinistisk seleksjon av bedrifter – små og lite produktive bedrifter blir erstattet av større og mer produktive. Artikkelen gir en oversikt over de grunnleggende mekanismene i den nye teorien samt noen sentrale utvidelser.

Trade barriers or trade facilitators? On the heterogeneous impact of food standards in international trade

Recent research shows that food standards can be heterogeneous across sectors or countries: they sometimes act as barriers to trade, but in other cases may lead to increased trade. We present empirical evidence from Norwegian seafood export data showing that food standards, measured by SPS and TBT notifications, generally have a negative impact on total exports, the number of exporters and their average exports. However, for fresh seafood, the impact of SPSs is positive. We present a theoretical explanation for this, suggesting that food standards reduce consumer uncertainty about quality and safety and therefore increase demand